Synopsis
The story centers on Kai, a gloomy middle school student whose life changes after meeting Lu, a mermaid.
Scores
Overall Score
45.3
Popularity Percentile (Year)
42.2%
Box Office Percentile (Year)
34.2%
Review Aggregate
71.7
Critic Consensus
Critic reception is largely positive, with 80% of 45 logged reviews marked Fresh. Across reviews, critics repeatedly emphasize lighthearted, stylized, visually striking. Most critics frame the film as an effective delivery of its core style and intent.
lightheartedstylizedvisually strikingfamily-friendlyemotionalgrittycharacter-drivensuspensefulfunnycoming of age
Cast
| Cast | Year | Reported Salary | Inflation Adjusted | Notes |
|---|---|---|---|---|
| Kanon Tani | 2018 | $2,000 | $2,000 | (est) |
| Shōta Shimoda | 2018 | $1,000 | $1,000 | (est) |
| Shinichi Shinohara | 2018 | $1,000 | $1,000 | (est) |
| Akira Emoto | 2018 | $1,000 | $1,000 | (est) |
| Soma Saito | 2018 | $1,000 | $1,000 | (est) |
| Minako Kotobuki | 2018 | $0 | $1,000 | (est) |
| Chidori (Daigo, Nobu) | 2018 | $0 | $1,000 | (est) |
Aggregated Reviews
Rotten Tomatoes critic score78.0
RT critic review count46
Rotten Tomatoes audience score67.0
RT audience rating count100
IMDb rating6.8
IMDb votes2,886
Box Office ?
| Category | Year | Reported | Inflation Adjusted |
|---|---|---|---|
| Domestic | 2018 | $109,857 | $137,245 |
| International | 2018 | $51,396 | $64,209 |
| Worldwide | 2018 | $161,253 | $201,454 |
Earnings / Profitability
| Category | Year | Reported | Inflation Adjusted |
|---|---|---|---|
| Revenues | |||
| Theatrical Net Revenue | 2018 | $75,487 | $94,306 |
| Digital Rentals ? | 2018 | $1,256,000 | $1,569,125 |
| Digital Purchases ? | 2018 | $1,515,000 | $1,892,694 |
| Physical Rentals ? | 2018 | $774,000 | $966,961 |
| Physical Purchases ? | 2018 | $2,195,000 | $2,742,220 |
| TV & Streaming Revenue | 2018 | $54,928 | $68,622 |
| Total Revenues | 2018 | $5,870,415 | $7,333,928 |
| Expenses | |||
| Budget ? | 2018 | $250,000 (est) | $312,326 (est) |
| Print & Advertising (P&A) ? | 2018 | $129,000 (est) | $161,160 (est) |
| Participations | 2018 | $235,000 | $293,586 |
| Residuals ? | 2018 | $295,000 | $368,544 |
| Interest & Overhead | 2018 | $50,000 | $62,465 |
| Total Expenses | 2018 | $959,000 | $1,198,082 |
| Movie Net Profit or Loss | 2018 | $4,911,415 | $6,135,846 |
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|---|---|---|---|---|---|
 | Roadside Romeo | 2008 | Shared genres: 7 | 39.5 | $6,176,329 |
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 | Turning Red | 2024 | Shared genres: 6 | 87.3 | $-191,490,851 |
 | Trolls | 2016 | Shared genres: 6 | 86.9 | $-30,273,291 |
 | KPop Demon Hunters | 2025 | Shared genres: 6 | 84.3 | $3,472,181 |