You decide to ask Sonoko out officially to be your girlfriend. This feeling needs to be explored more, you think to yourself. She heartily agrees and she attempts to do everything she can to make you a happy man. Yet you yourself don't feel quite happy; you notice that you're still looking at young men as they pass by, completely forgetting Sonoko's existence for that time being. Realising that you don't share the same feelings, Sonoko begins to get depressed. Not sure what is wrong exactly, you feel guilty for bringing Sonoko this pain and try to make up for it by proposing to her. Accepting, you two have decided to link yourselves to one another for eternity into a mental pain.