"Underwear" is a fascinating item. It has the magical power to confuse men and remove the limiter of reason. Yuka is a girl who thinks about how to wear underwear every day and extends a hand of grace to lambs who are troubled by how to wear underwear. It may be hard to believe that she is so knowledgeable about underwear at the young age of 19, but there is a story behind it that cannot be told without tears. That was right after she entered high school, and she still loved sports bras, having played basketball since junior high school. All her friends around her were at a sensitive age where they were paying attention to the latest underwear, but she decided to wear only sports bras, no matter what people said, because of her own policy and ease of movement. Although she is such a straightforward girl, she eventually falls in love and begins to show a glimpse of her femininity. The person she likes is a senior in her club. He is a perfect guy who always has a refreshing smile, is kind to everyone, and is popular with everyone. She fell in love with him, but she didn't know how to fall in love, and there were many rivals, so she didn't approach him very actively because she felt that she would rather get involved in troublesome things. With such a secret feeling, she worked hard at her club activities. One day, while spending her time like that, she happened to go home at the same time as a senior student she admired, and they ended up going home together. She walked home from school while secretly feeling happy to hear his voice and smile while talking about trivial things. She walked home with him like that several times after that. Then they exchanged email addresses, and the distance between them quickly decreased. Then one day he confessed his feelings to her, and of course she said OK, and they started dating. Then on the day they first tied together, she melted from his sweet kiss at the beginning, and he took off her jacket. His pants were already tenting so much that they were about to burst. She was ready to give herself to him. And the moment she exposed her underwear, he said the word "eh". She didn't know what he meant, and at first she thought she had misheard. Today she was wearing her favorite sports brand bra, and she couldn't think of a reason to say such a thing. From then on, his tent gradually lost momentum and became completely silent. That day, the two were not united. Some time passed from that day, but he never tried to ask for her body. And for some reason, he suddenly broke up with her. She was at a loss as to what to do. However, she really wanted to find out the reason for the breakup from him, so she decided to search through the people around him and ask them the reason. Then, while she was searching through various people, she happened to witness him talking with a friend. Thinking that this was her chance, she decided to listen in and hear what he had to say. Then she heard a shocking word from his mouth. "He was wearing a sports bra... It reminded me of my sister's underwear, and I was really turned off." And then she realized. Sports bras are for children. To become an adult woman, you have to change your underwear. After that incident, she studied underwear intensively, and now she wants to make it her job to teach the importance of underwear in order to reduce the number of girls who have such experiences.