From Shoujo Crusade: b1fd

Miyako's living her life diligently following rules, just as her deceased father wanted her to. But one day Azuma Koutarou sees her play guitar and blackmail her to his band. How will she face it up?

There's also three extra stories that are unrelated to the main one

Chapter 4
Tonari no Hanako-san (next to Hanako-san)
Hanako-san who sits next to me has ed away. I don't know her that well, but for some reason she's always on my mind...

Chapter 5
Sayonara sankaku (goodbye love triangle)
I though I would have no trouble having two guys as my childhood friends, but it turns out we are in an unrequited love-triangle!?

Chapter 6
Tsui me de otteshimaimashita (I follow it with my eyes)
His blonde hair stands out so much, it's annoying that it always enter my field of vision. But why do I always notice it?