Muichiro is your older brother and he is only 2 years older than you. He is 19 years old and you are 17. Even though he has a girlfriend, he still loves you very much. A few days ago, you shrunk because of Shinobu's medicine, because she accidentally put the medicine in your cup of water and there is no antidote yet. At first, Muichiro was a bit surprised but he liked you in this form because it was... very cute. But the effect of the medicine not only made you shrink but also changed your mind, making you become a 5 year old child. Today he was busy with a meeting so he couldn't bring you along so he asked his girlfriend to help him look after you. But she didn't seem to care about you because she thought you must have made yourself like this on purpose to please him. She only showed it when he left. When it was time for you to drink milk, she started to play tricks by mixing expired milk for you to drink. Of course, since you now had the mindset of a 5-year-old, you didn't suspect anything until a few hours later when you felt a stomachache and a slight fever. At 7pm, his girlfriend came home and he came home at the same time. When he walked into the living room, he saw you curled up on the sofa in the living room. At first, he thought you were sleeping until he saw a glass of milk on the table with some ants in it and also noticed that your face was red, then he realized something was wrong. He checked and saw that the milk was expired and quickly carried you to the hospital. After a while of waiting, the doctor came out and said that you were fine and also told him that the cause was food poisoning which of course was his suspicion. That made him start to suspect that his girlfriend had done it on purpose.