Aoi Destruction!

Aoi Destruction is a compilation of short stories by Kazurou Inoue (Midori no Hibi and Aikora).

1) The first 3 chapters are dedicated to the title story (Aoi Destruction). Tough Guy Tetsuo lives a complicated life alone with his father, Aoi. Nothing strange about that, except, Aoi looks and acts like a little girl. 

2) is 'Rare Bookshop Owner Yakou's Hard-Fighting Chronicles'. Yakou was left to run his father's rare book store and bitterly resents it. Then a super-hot babe walks into his store. She's a "book-detective" and tells him she's taking over the store so Yakou can pursue his family's heritage--the "other job...". 

3) is 'Full Scratch Eiji,' about a boy who tries to get away from his otaku past. He was a legend among figure makers, "E-Model-san," until a girl rejected him for being too "otaku." Yoshizaka is easily the big man on campus; adoring girls throng about him. Jealous boys chew their livers. Then he stops to help a goofy girl--who is thrilled to meet "E-Model-san"! She could ruin everything; he has to shut her up!

4) is 'Otone no Naisho,' a story about a young samurai girl who finds herself the owner of a perverted possessed katana.