AKITSORA GAMING

Tanabata Star River

Once a year, the magpies build a bridge.

Tanabata Star River spins two 5×3 grids across the Milky Way: wilds mirror to the far bank, and in free spins the grids join into 10 reels where magpie flocks multiply.

Demo play uses virtual credits with no monetary value.

RTP
96.59%
Volatility
Medium-high8.56
Max win
10,000× bet
Bonus buy
76.80 / 98.52× bet

In-game screens

Captured straight from the running game — real boards, real wins.

Tanabata Star River — Base game
Base gameTwo 5×3 grids face each other across the Milky Way — the Weaver on the left bank, the Herdsman on the right — each paying 243 ways.
Tanabata Star River — Both banks
Both banksA magpie landing on one side flies to the mirrored spot on the other; winning symbols light up and stardust flies into the win.
Tanabata Star River — Star meeting
Star meetingThe two grids merge into one 10-reel grid. Each magpie calls a full-reel flock, the flock count is the multiplier, and a finished bridge doubles it again (×2).
Tanabata Star River — Big win
Big winA single round is capped at 10,000× the bet.
Tanabata Star River — Bonus buy
Bonus buyTwo tiers: ×76.80 Star meeting, ×98.52 Star meeting — bridge underway (opens with 2 flocks).
Tanabata Star River — In-game paytable
In-game paytableFrom the same game definition as this page: served by the RGS in game, read at build time here.

Specification

TypeBase game: two grids of 5 reels × 3 rows (243 ways each); free spins: one 10-reel grid (59049 ways); 3+ consecutive reels from the left
Return to player (RTP)96.59%
Bonus buy RTP (Star meeting)96.59%
Bonus buy RTP (Star meeting — bridge underway)96.59%
VolatilityMedium-high (8.56)
Hit rate36.52%
Rounds winning ≥ 1× bet13.87%
Max win per round10,000× bet
Star meeting (free spins) frequency≈ 1 in 189.54 spins
RTP verificationExact base game + 101,000,000 feature samples; combined RTP 96.5969%, 2σ margin ±0.0090 percentage points; independent implementation (separate code, not the engine) with 6,000,000,000 feature samples: combined RTP 96.5904%, 2σ margin ±0.0024 percentage points

Game math specifications and the paytable are read at build time from the definitions shared with the server code. See Math version for the configuration shown; confirm any other version or operator-specific settings separately.

How wins work

  • The base game is two grids of 5 reels × 3 rows on either bank of the Milky Way — the Weaver's bank on the left, the Herdsman's on the right. Each grid pays on its own and the wins add up (243 ways each, no paylines).
  • A win needs the same symbol (or a magpie) on every reel in a row from a grid's leftmost reel, at least 3 reels; the pay = table value × the product of matching symbols per reel.
  • The magpie is a wild on reels 2–4 of each grid; when one lands, the mirrored spot across the river becomes a magpie too.
  • Stars count anywhere — Vega on the left, Altair on the right: 3 or more across both grids start the Star meeting (free spins).

Paytable

This is the free-spins paytable (the two grids joined into 10 reels): values are multiples of the total bet for one way, win = total bet × table value × the product of matching symbols on each reel × the spin's magpie multiplier. In the base game each grid uses its own 3–5-reel paytable, shown below.

Symbol3 reels4 reels5 reels6 reels7 reels8 reels9 reels10 reels
LoomHigh-pay 0.0970.2420.5820.971.5512.4243.87870
CalfHigh-pay 0.0730.160.3640.5820.8731.3092.0362.909
Star hairpinHigh-pay 0.0610.1210.2420.3640.5450.7881.1511.636
Moon boatHigh-pay 0.0480.0970.1940.2670.3880.5330.7271.018
Paper streamerLow-pay 0.0240.0390.0610.0780.0970.1210.150.182
Paper kimonoLow-pay 0.0240.0390.0610.0780.0970.1210.150.182
Drawstring purseLow-pay 0.0190.0310.0480.0620.0780.0970.120.145
Paper cranesLow-pay 0.0190.0310.0480.0620.0780.0970.120.145

Base-game paytable (5 reels per grid)

In the base game each of the two grids is evaluated with this table and the wins are added: values are multiples of the total bet for one way, win = total bet × table value × the product of matching symbols on each reel. Wins start with 3 consecutive reels from that grid's leftmost reel.

Symbol3 reels4 reels5 reels
LoomHigh-pay 0.581.453.5
CalfHigh-pay 0.441.12.8
Star hairpinHigh-pay 0.340.882.15
Moon boatHigh-pay 0.290.681.7
Paper streamerLow-pay 0.1450.340.82
Paper kimonoLow-pay 0.1450.290.68
Drawstring purseLow-pay 0.1150.210.58
Paper cranesLow-pay 0.1150.210.58

Special symbols

Magpie

Wild on reels 2–4 of each grid; in the base game it also appears at the mirrored spot across the river.

Magpie flock

Free spins only: a landing magpie fills its reel (and the mirrored reel) with a flock (wild, counting as 1 symbol on that reel); the flock count is the multiplier.

Vega & Altair

Count anywhere: 3/4/5 across both grids start 10/12/15 free spins. Vega on the left, Altair on the right.

Features

Mirrored magpies

A magpie landing on reel c of one grid flies across the river: the same row on the mirrored reel of the other grid turns into a magpie as well. If that spot holds a star, the star stays (magpies never cover stars).

Star meeting — the grids join

3/4/5 stars start 10/12/15 free spins: the two grids slide together into one 10-reel grid, paying from 3 consecutive reels on the left (up to 59049 ways). 3 more stars add 5 spins.

Magpie flocks — the flock count is the multiplier

In free spins a magpie turns its whole reel into a flock (one wild match on that reel) and the mirrored reel follows; flocks stay for the rest of the feature. Each spin's ways wins are multiplied by the number of flocks (up to 8).

The magpie bridge

Reels 2–9 pair up into four bridge sections. With all four built the bridge is complete: the Weaver and the Herdsman meet in the middle and the multiplier doubles from that spin on — 8 flocks × 2 = ×16.

Gazing across the river

If the two reels beside the river both show a star on the triggering spin, the Star meeting opens with the middle of the bridge already built (2 flocks, starting at ×2).

Volatility — positioning

Volatility 8.56. Hit rate 36.52% counts rounds with any win; 13.87% of all rounds return at least the stake. The base game carries about 57% of the RTP and the Star meeting arrives about once every 189.54 spins; the bridge is often completed, and those runs are where the big wins come from. Capped at 10,000× the bet per round. This describes the product's positioning and does not guarantee session outcomes.

Bonus buy (two tiers)

Pay 76.80× the bet to start the Star meeting directly (10 spins), or 98.52× for one that opens with the middle of the bridge already built. Each price comes from the expected value measured along its own path (buy RTP 96.59% / 96.59%) and is calibrated separately from the base game.

Technical

Game codeaki_tanabata
Math versiontn1
TechnologyHTML5, no plug-in; one client for desktop and mobile
ViewportLandscape with proportional scaling
In-game languageTraditional Chinese (additional languages on request)
CurrenciesTWD (others can be registered on request)
IntegrationTransfer wallet (Operator API v3), launch-token redirect

Sources & verification scope

This product specification is written and maintained by its developer, Akitsora Gaming (AKI電子 in Taiwan). Measurement methods and sample information for RTP, volatility and hit rate appear in the specification table. Sampled results have uncertainty; RTP describes long-run return, not an individual player or session outcome.

Internal simulations and tests are not independent certification. We do not currently hold GLI or BMM certification reports. Supply to a market requiring third-party certification depends on completing its requirements.

See slot game development and supply for integration and supply scope, About us for development and content responsibility, or contact us for a math summary, version confirmation or a correction to this page.

The story

Fiction and adapted settings written by Akitsora Gaming for this title, including invented dialogue and events. This is not a historical or folklore reference. The rules and specification tables define the gameplay and math.

Silent flows the silver river, parting east and west in longing,
until the seventh night, when magpies link their wings into a starry bridge.

I. Two Banks of the Silver River

In the ancient star legend, Orihime, the Weaver Princess and daughter of the Lord of Heaven, sat on the eastern bank of the Milky Way weaving cloth of starlight, while on the western bank lived Hikoboshi, a devoted young herdsman. When the two met and fell deeply in love, they spent every waking hour together — the celestial loom fell silent and the cattle wandered across the clouds.

Angered by their neglect, the Lord of Heaven drew a wide silver river across the sky to set them on opposite banks, allowing them to meet only once a year. The base game reflects their separation: two distinct five-reel grids spin on either bank of the glowing Milky Way, each evaluating its own ways from the left while gazing across the water. Shimmering starlight ripples along the current between the two banks as the summer evening deepens into night.

II. Magpies Across the Milky Way

Even with the starry river flowing between them, every message finds a way across the night sky. Whenever a magpie wild lands on one bank's grid, it takes wing over the Milky Way and mirrors itself onto the exact opposite reel and row on the far bank, helping both sides complete combinations on the very same beat. With every wingbeat across the silver water, the two separated shores feel a little closer to their long-awaited reunion.

Better still, if the two reels standing right beside the riverbanks both shine with Vega and Altair on the spin that triggers the feature, the lovers have caught sight of each other across the water — opening the Star Meeting with the central spans of the magpie bridge already built and ready. That early meeting across the water sets a radiant tone for the entire feature before the first free spin even begins.

III. Five-Coloured Wishes at Hoshi-ai

In Japan, the seventh night of the seventh month is known as Hoshi-ai, the meeting of the stars. Townsfolk write their wishes on five-coloured paper strips called tanzaku, tie them to freshly cut bamboo branches along the streets, and look up toward the two bright stars flanking the Milky Way in the summer sky. Lanterns glow warmly along the wooden verandas as the rustle of bamboo leaves carries those written wishes up toward the heavens.

When enough Vega and Altair stars gather across both banks on a single spin, the night of Hoshi-ai begins in earnest: the two separate grids slide together across the river and unite into a single wide stage of ten reels, letting combinations flow unbroken from the left shore all the way to the right. What were once two distant shores now beat as a single starry expanse where every symbol can travel all the way across.

IV. The Bridge Completed at Midnight

During the Star Meeting, any magpie that lands calls in a whole magpie flock to fill its entire reel — and its mirrored reel across the river as well — staying locked in place for the rest of the night. The total number of flocks on the board acts directly as the win multiplier on every spin. Wing to wing across the heavens, the gathering flocks turn the dark river of night into a gleaming path of silver and gold.

Once all four paired sections across the middle reels are filled with flocks, the magpie bridge is complete: the Weaver and the Herdsman walk out from opposite shores to meet at the centre of the Milky Way, doubling the flock multiplier for every remaining spin of the feature. Under the canopy of midsummer stars, the completed bridge celebrates their once-a-year embrace with the brightest payouts of the night.

Want to spin Tanabata Star River yourself?

The demo needs no account — click and spin. For integration docs, the math summary or sandbox access, send us an email.

Demo play uses virtual credits with no monetary value.