Merman in My Tub Review: A Boy Discovers a Merman in the River and Moves Him into His Bathroom
by Itokichi
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Quick Take
- A gentle supernatural domestic comedy that works through the specific absurdity of sea creatures in a small apartment — the bathtub as ocean substitute generates consistent situation comedy
- The implied romantic dynamic between Tatsumi and Wakasa is drawn with lightness rather than force
- 11 volumes complete; comfort reading with a distinctive premise
Who Is This Manga For?
- Readers who want supernatural domestic comedy in an apartment setting
- Anyone interested in boys' love adjacent content with gentle implied romance
- Fans of unusual roommate comedies with sea creature variety
- Readers looking for complete light slice-of-life
Content Warnings & Age Rating
Age Rating: T (Teen) Content Warnings: Boys' love implied romantic subtext; sea creature characters with humanoid elements; domestic comedy situations
T rating — gentle content; the implied romance is not explicit.
Yu's Rating
| Category | Score |
|---|---|
| Story Depth | ★★☆☆☆ |
| Art Style | ★★★★☆ |
| Character Development | ★★★☆☆ |
| Accessibility for Non-Japanese Readers | ★★★★★ |
| Reread Value | ★★★☆☆ |
Story Overview
Tatsumi is a practical, serious young man living alone in a small apartment. Wakasa is a vain, cheerful merman who does not want to leave the bathtub Tatsumi put him in.
This is the premise, and the series develops it through domestic accumulation: more sea creatures arrive — an octopus, a jellyfish, a sea slug — each adding to the supernatural household. Wakasa's vanity and his affection for Tatsumi run in parallel, and Tatsumi's long-suffering practicality is consistently tested by requests that no apartment is designed for.
The series does not need more than this to work as a comedic format across 11 volumes.
Characters
Tatsumi — The straight-man whose practical responses to completely impractical situations are the comedy's grounding.
Wakasa — The merman whose combination of genuine warmth and total self-absorption makes him a specific kind of comedic character.
The sea creature visitors — Each with a different personality appropriate to their species, adding variety to the apartment dynamic.
Art Style
Itokichi's art captures the specific visual challenge of sea creatures in domestic settings — the bathtub scenes, the various sea creature character designs, and the apartment's gradually overwhelmed state are drawn with warm, clean character work.
Cultural Context
Merman in My Tub ran in Comic Alive from 2012 to 2019. The series participates in the "supernatural being in domestic space" genre that includes many Japanese slice-of-life manga, distinguishing itself through the sea creature specificity and the boys' love adjacent romantic subtext.
What I Love About It
The bathtub as ocean. Wakasa treats Tatsumi's bathtub with the same possessive comfort he would treat a proper sea territory. The gap between how Wakasa experiences the bathtub and how Tatsumi experiences it — as his bathroom — is the series' most consistent comedic foundation.
What English-Speaking Fans Say
Western readers describe Merman in My Tub as light, pleasant comfort reading — specifically noted for the sea creature variety keeping the premise fresh across 11 volumes, for the implied romance being handled with appropriate gentleness, and for the domestic comedy being consistently funny without needing escalation. Recommended for readers who want supernatural domestic slice-of-life.
Memorable Scene ⚠️ Spoiler Warning
Any chapter where the apartment's unusual population creates a situation that Tatsumi must explain to an outside visitor — the gap between the supernatural reality and normal expectations — is the series' most comedically efficient content.
Similar Manga
- Miss Kobayashi's Dragon Maid — Supernatural being in domestic space in different register
- My Roommate is a Cat — Unusual domestic companion slice-of-life
- A Man and His Cat — Gentle domestic companion warmth
- Chi's Sweet Home — Domestic companion slice-of-life in lighter register
Reading Order / Where to Start
Volume 1 — Wakasa's arrival and the first domestic situation establish the premise.
Official English Translation Status
Square Enix Manga published the complete English series. All 11 volumes available.
Pros & Cons
Pros
- Premise is distinctive
- Sea creature variety maintains interest
- Gentle and consistently pleasant
- Complete in 11 volumes
Cons
- Light depth — not attempting more than comedy
- Formula becomes familiar around midpoint
- Implied romance may frustrate readers who want it developed
Format Comparison
| Format | Notes |
|---|---|
| Individual Volumes | Square Enix Manga; complete series |
| Digital | Available |
Where to Buy
Get Merman in My Tub Vol. 1 on Amazon →
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*Affiliate link — I earn a small commission at no extra cost to you.
Written by
Yu
Manga Enthusiast from Japan
I grew up in Japan and manga literally saved me during a tough time in elementary school. My English isn't perfect, but my love for manga is real — and I want to share it with you.
Disclosure: This post contains affiliate links. As an Amazon Associate, I earn from qualifying purchases at no extra cost to you.