Natsu no Teppen ni Saku

Overview

"If only I could be Yousuke's boyfriend." I've known Yousuke since I was young, he's my best friend and we've always been together. Every summer, Yousuke and our group of friends would hit the beach, watch fireworks, go to festivals... That's how I thought we'd be spending our days this summer, until that one day when Yousuke got a girlfriend. Seeing Yousuke's girlfriend by his side made my chest ache. Seeing Yousuke fully devoting himself to his part-time job just to go on a date with his girlfriend bothered me. It didn't take long before I realised that this was the very definition of "jealousy." My feelings for Yousuke grew with each passing day, until one day, my feelings overflowed... Note: Includes two extra chapters.

Source: AniList