Seven Days (manga)

"How about it? Why don't you go out with me, Seryou?"

Seven Days is a two-volume Boys Love manga written by Benio Tachibana and illustrated by Rihito Takarai. The first volume has been translated and released in English.

Touji Seryou was famous in his school for his good looks and an unusual habit: he would go out with anyone who confesses to him first on Monday, be a perfect boyfriend and then break up with that person a week after. One Monday, Yuzuru Shino, a male senior, asked Seryou out on a whim to see how he would react and Seryou accepted. Thus, the two started a seven day relationship.

Not to be confused with a UPN series about a time-traveling mental patient.

Tropes used in Seven Days (manga) include:

Brilliant but Lazy: Common opinions regarding Seryou and archery.
The Casanova: Seryou seems to be one but in truth he is serious about relationships, just in a rather abnormal way. He is also a bit of a Chaste Hero.
Hidden Depths: The Aesop of the story
Lap Pillow: A rare male-male example in volume 1.
Japanese School Club: Both Yuzuru and Seryou are talented members of archery club at school.
Looking for Love In All the Wrong Places: Seryou's one-week dates is to find a person whom he can love and who loves him. Ironically, that only makes the people who date him think they are just his flings and consequently treat the relationship as a weekly habit.
Name's the Same: Yuzuru's surname and the name of Seryou's first crush are both pronounced Shino (but written with different kanji), prompting Seryou to ask for Yuzuru's permission to be on First-Name Basis right away when they first went out.
Seme and Uke: Unusually, averted. Neither of the two main characters fits obviously into either role at all.
Sempai-Kohai: Yuzuru is Seryou's sempai.
Sleep Cute: Yuzuru on Seryou on their date at the movies.