Cat and Salt, or Sugar.

Ichiro is a 32-year-old man who has voluntarily become his mother's "pet," retreating from the flow of life suggested by society: university, career, marriage, parenting, home ownership. His quiet life at home (with an alcoholic father) is interrupted when the ex-boyfriend of Ichiro's mother and his "white idol" daughter move in. Under a cramped roof, the five search for happiness.