I Know What You Did Last Summer: the manga.
Until Your Bones Rot (Hone ga Kusaru made) is a psychological-horror, mystery manga by Yae Utsumi that ran from May 1, 2016 to February 11, 2018, with 7 volumes total.
Five childhood friends: Shintaro, Tsubaki, Haruka, Ryu, and Akira have been performing a ritual every summer festival for the past five years. Five years ago, they killed someone, so they perform a ritual to never forget, to never betray. A secret they will take to the grave. But now someone else knows, and a single phone call changes everything.
Tropes contained in Until Your Bones Rot
- Abusive Parents: Shintaro was physically beaten by his father. It's why his friends killed him.
- However, Shintaro did not want to kill him in the end, having realized that even though his father was awful and required help in some form, he learned his father truly did love him, albeit too late.
- Akira's mother was intensely strict with him.
- Affectionate Nickname: Shintaro is called "Shin" by his friends.
- Amateur Sleuth: Shintaro is the one who slowly begins unraveling the mystery surrounding the mysterious caller and the bones disappearing.
- Becoming the Mask: Tsubaki was the mastermind behind the events of the series, all done in efforts to keep their secret and her friends safe.
- Boyish Short Hair: Both girls had it at different stages of their life, as a child, Haruka had it, in their teens, Tsubaki has it.
- Childhood Friends
- Deceased Parents Are the Best: Shintaro is an orphan, his mother died of illness and his father was the person they murdered. Despite going a majority of the series claiming his father deserved death, it is later revealed Shintaro truly did not want to kill his father.
- Disappeared Dad: The person the kids killed was Shintaro's father.
- Disposing of a Body: The kids are tasked by the mysterious caller to dispose of a body by chopping it up and burying the remains in different places.
- They later have to do the same thing with Akira's body.
- Disproportionate Retribution: Averted, the kids confess to their crimes in the end: Ryu, Haruka, and Shintaro all serve two years in juvie for being accomplices, Tsubaki is sentenced to 8 to 13 years for first degree murder for her actions over the course of hiding their secret, she is released on parole four and a half years later due to genuinely regretting her actions and in general good behavior.
- Dragged into Drag: Part of his abuse, Shintaro's father made him crossdress and told him he'd grow up to be a woman.
- Dropped a Bridge on Him: Akira is murdered about a third of the way through the series.
- Hero Worship: Akira and Shintaro view each other as heroes, Akira is a more played straight example.
- Japanese Delinquents: Ryu used to be one.
- Missing Mom: Shintaro's mom died of illness when he was young, triggering his abuse.
- Never Found the Body: The kids spin a tale that Akira fell off a cliff that has a high suicide rate and low body turnover to the police, they in actuality buried his body elsewhere, and the police never find it.
- Love Dodecahedron: Ryu is in love with Haruka, who loves Shintaro, who loves Tsubaki, who reciprocates but is also in a relationship with Akira.
- Official Couple: Tsubaki and Akira are dating. Tsubaki later confesses she was only dating him to keep him from trying to turn himself into the police.
- The epilogue implies Ryu and Haruka will be dating in the near future, and now that Tsubaki is out of prison, she and Shintaro will most likely get together.
- Red Herring: Shintaro has a warning in his yearbook to be careful of Akira, causing suspicion to him and the readers. However, Akira is killed soon after and the details of the note become clear later.
- The Reveal: The mysterious caller was an old teacher of their's who was a child predator who was interested in Haruka and knew their secret, Tsubaki sacrificed herself to divert his attention from her and to keep his mouth shut; the two of them worked together throughout the years to ensure the secret would stay hidden.
- Secret-Keeper: All five of them keep the secret of their crime. As they get older and with the events of the series unfolding, some of them begin to feel they can't keep it anymore.
- They all agreed to not hide anything from each other anymore, however, as the events unfold, it becomes clear not all of them are being truthful.
- The Stoic: Shintaro.
- Not So Stoic: As an adult, he's become more emote, however, it is forced.
- Strong Family Resemblance: Shintaro is a near carbon copy of his mother.
- Tomboy: Haruka was one in as a child.
- We Hardly Knew Ye: All the reader truly gets of an impression of Akira is he's very devoted to Shintaro and is potentially suspicious for the bones disappearing, then he's murdered not even a third into the series.
