Hanabi's short fused and pushy yet sweet childhood friend. They were friends since birth and next door neighbors. He claimed to have practically raised Hanabi. He trained Hanabi to be strong. Ultimately making her who she is now. He moved to Denmark when Hanabi began elementary school because of his father's work, but promised to return when she became really strong. Ten years later, he returned to Japan to fulfill his promise. He came for a short period of time to look for houses in the area. He told Hanabi to break up with her boyfriend to be with him. He took Hanabi to a love hotel to 'make her a woman', but they didn't go in. However, they were spotted by Hanabi's schoolmates who misunderstood the situation and spread the gossip around school. Yasuaki squashed that rumor immediately by saying that Hanabi was just showing an old friend around town. Yasuaki was still jealous though, and spoke harshly to Hanabi, assuming that she and Takeru were together. She got upset and proclaimed that she chose Takeru, not wanting to hear anymore of Yasuaki's mean words. Hanabi was going to tell Takeru her decision when she found that Takeru and Yasuaki got into a fight. She immediately ran to Yasuaki and realized who she really chose. Yasuaki admitted to being jealous of Takeru and mentioned that the two acted and talked in the same way. Takeru told Hanabi to meet him at the airport to answer his confession, but she called him instead and told him she chose Yasuaki. He told Hanabi that if you just try something, you may actually have fun. Takeru returned later, with no signs of backing down. He took Yasuaki and Hanabi to pick up Hanabi's father at the airport. Hanabi's father got bad first impressions of Yasuaki and said that he preferred Takeru. He even called Takeru and Hanabi 'Takebi'. It turned out that he was only testing Yasuaki and Yasuaki passed his test, giving his approval for the relationship. Hanabi finally stood up to Takeru when he offered to pick her up and take her home but she declined, spending the night with Yasuaki instead.