Opus posthumous

Tanaka is a young man who has a vague dream of becoming a painter and manages to make a living as a day laborer.
Tanaka lives with a girlfriend. Every day, she quits painting and tells Tanaka to do a stable job. At work, my boss dominates Tanak with violence and rants, leading a stressful life.
One day, when Tanaka come home, the picture's was thrown away. That led him to quarrel with her and run away from home.
After that, he contacted Yasuda who is a junior high school friend, and met again after a long time. Yasuda is the only person who can rely on Tanaka.
They started "practice" to kill her to relieve Tanaka's stress.