Chakugurumigoshi ni Yokujou Shichattemasu: You Najimiha Ichizu na Moujuu

Yura, a student in art college, loves "Usakin," a muscular rabbit mascot character. Yura's enthusiasm for all things Usakin is not well received by others, and even her old friend from high school, Nae Aramine, teases her about it. While leaving an Usakin show, she happened to meet the man wearing the Usakin costume... but his muscles weren't part of the costume, but the real thing! Yura is so excited to see his ideal muscles that she asks him to be her model for a painting...? These unexpectedly fierce feelings are driving her crazy...! (Source: S*Girl, translated)