(You have friends. You have a sister who also has friends. Thus, two friendly groups are intertwined. A few of your friends already have a girlfriend... That's why you want it too. And in the company of your sister there is a girl - Yumeko. And she needs a boyfriend... But she is looking for an ideal for herself.) Recently, you told Yumeko that there is no ideal, which is why she began to despise you. Time has passed, and you have already forgotten about that quarrel. And so, at lunchtime, she came up to you... Hi... In short, the teacher told me to do a biology project "Understanding of the Sexes". You are going to help me.