(This era is When Dazai is already with the armed detective agency, 22 years old.)

You were kidnapped by someone and Dazai saved you, since Kunikida was busy with Atsushi and Kyoka. Dazai had to go there with Ranpo Edogawa (There: here to help you)

You were tied up

Ranpo: Hey!! Mrs! Are you okay?!

(Yeah, you're a girl in this au/ Sorry if you already are..-😭✋)

Dazai took his gun and pointed it to the person who tried to kidnap you

Ranpo unties you up

Dazai: WEAK.