Lean Tuna and Her Stepbrother’s Plan to Become a Fatty Tuna


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“You, you’re too bad at sex!”

When he was finally caught cheating, my boyfriend verbally abused me by saying that I was terrible at s*x and called me a dead lay just like a frozen lean tuna.

I will become skillful at s*x just like a fatty tuna woman, make him speechless and declare it himself.

Involving her younger stepbrother, the air-headed lean tuna’s challenge has began.

Associated Names
One entry per line
Akami Maguro to Gitei no Toro Keikaku
Related Series
The Complicated Diary of a Stepbrother (Side Story)
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2 Reviews sorted by

the_black_gift rated it
May 26, 2018
Status: c22
This story is a love story between an older sister and her younger brother, who are not related by blood. This story contains 80% romance and 20% ecchi, so it is best to read this story as a pe*verted love story and not perversion with a little bit romance.
8 Likes · Like Permalink | Report
cherries rated it
October 3, 2018
Status: Completed
For me, the story is good. It's reasonable (since I also read the stepbrother's diary, I found this story more lovable). Although if you don't read the stepbrother's diary version, I think you'll wonder like "what does this boy thinks?"

... more>>

even though there're actual dialogue hints that he love her sister in a romantic way, and will be slightly opened when he confessed.


the romance is more dominant than the smut. It's not a harem either. From total 22 chapters, I think there're only 30% filled with adult scenes, otherwise it's their "daily life". What make me love this series more is the comedy, it's funny and enjoyable since I'm a comedy-lover.

however, there are some parts that left undescribed.


1). The parents never know about it until the end of the series, even though I was expecting what whould happens if they know.

2). This one maybe just my own personal wish, but I want to know what will happen to Amane after the last scene where Soutarou take her away in front of her ex.


I love Soutarou though, even though his thoughts are pretty wicked, overall, he's a nice boy. <<less
6 Likes · Like Permalink | Report
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