Scumbag, Stay Away from My Sister

Nakahara Chuuya swears that if Dazai so much as lays a finger on his big sister, he'll make him regret it.

Chuuya: Big Sis, stay away from that walking lump of coal. He's no good!

Big Sis: ...? (Looking at her little brother, one head in each hand, covered in blood.)

Please note:

I've only watched the anime, so I'll mostly skip the parts about Chuuya at sixteen. I wanted to try writing them, but I'm worried my interpretation will stray too far from the original, so I've decided to skip them.

Dazai is the type to fall for her through his own schemes. The female lead is loved by everyone, so keep that in mind before reading.

Most of the other strange settings are things I made up, so please don't be too harsh or I'll suddenly stop updating.

I'm writing this just for fun.

Theme: Suddenly felt like reading about a sister-obsessed character.