Yankee Onii-san wo Munekyun Saseru Houhou
ヤンキーお兄さんを胸キュンさせる方法 · やんきー おにいさん お むねきゅん させる ほうほう
est. Rough estimate based on volume count, reprints and magazine — not an official figure
Overview
Hajime, a straight-laced high school student, fell in love at first sight with Mitsuru, a Yankee who helped him one day. Since Hajime has no experience in love, he starts approaching Mitsuru while studying shoujo-manga. And when he starts to pay attention to his appearance in order to become the man Mitsuru likes, Hajime suddenly starts to get popular...!? (Source: Kadokawa, translated) Note: Chapter count includes 2 extras.
Source: AniList
External databases: MADB · AniList
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections