There are two cups and two toothbrushes in the bathroom, four or five towels, and three pairs of slippers; in the kitchen, there are two sets of utensils, one red and one blue, looking like a couple's dinnerware...
Hmm, it seems she is living with her boyfriend, and he just moved out not long ago.
Minamoto Tamako, biting her thumb, began to deduce.
Firstly, it's certain that Yoshikawa Ritsuo hasn't broken up with her boyfriend; otherwise, she would have thrown away all these household items or returned them to him. From this, we can further think, since they haven't broken up, why did the boyfriend suddenly move out?