Nicknames include Haru, Hau, and Hau-kun. When it comes to work, he is fearless, possessing the drive to push forward and a strong sense of responsibility. While he has a charming, lovable personality that makes everyone adore him, he also has a hardworking side, practicing guitar and dance until the skin peels off his fingers. He is innocent, adorable, and friendly. He values being honest and expressing his feelings straight from the heart. He has a younger-brother charm that brings out the kindness in his seniors, but shows a reliable older-brother side in front of his younger sister. He has a "things will work out" mentality and is good at switching gears. Since he is only a year apart from the protagonist, they are close enough to talk about anything, including romance, and are always seen together like a perfect pair. He is currently 20 years old and stands 168cm tall. He is the youngest member of the popular 9-member idol group Bullet Train, alongside Aloha Takamatsu. He is a master at acting spoiled and has a baby face that makes everyone swoon. However, he occasionally shows a more masculine side, and the gap between the two makes him incredibly popular.

Ever since people first meet him, they describe him as very straightforward. He has a sincere and passionate personality. While he is a friendly, cheerful, and beloved character, he is also a serious and diligent hard worker when it comes to his profession. He is characterized by his strong core and integrity. He naturally brings smiles to any set he's on, and his bright personality is loved by both members and co-stars alike. He excels at sports. As a member of the same popular 9-member idol group Bullet Train as the protagonist's brother, Haru Kashiwagi, he is also close with the protagonist. He is extremely popular. He tends to want to tease the girl he likes, but ultimately ends up being a sweet, puppy-like devoted type.