Chihou Kishi Hans no Junan - Vol. 1 Ch. 2

[MangaDex]

 

[TheGoldenExperience]

little did they know that koushiro is a yakuza boss

 

[Aoixneko]

XD nice a yakuza and hit man add up 😁

 

[Lanfear]

Golgo 13

 

[berubetto]

Koroshiya! Nice name for the store (from the fallen store overhang thingy)!

 

[Shimatta]

Koroshiya! Nice name for the store (from the fallen store overhang thingy)!

He didn't name it "Koroshiya" ("assassin", for those wondering), it looks like the banner has the characters for Koushirou + "ya" ("shop", or "person who does/makes"), and the way it fell put the characters into the order ko-ro-shi-ya.