Ryūnosuke is tall teenage boy with dark blue hair that is tied in a short ponytail at the base of his neck and grey eyes. He is usually seen wearing his school uniform. Ryūnosuke also is seen wearing a necklace.
Like Ikuto Sarashina (Ikkun) and Naoya Shirokawa (Shiroyan), Kurotatsu initially disliked Misaki Ayuzawa and harassed her. His behavior, as well as that of his two friends, would change upon seeing Misaki working as a maid in Maid Latte. Unlike Naoya and Ikuto, Ryūnosuke seems primarily interested in Misaki's sex appeal, as he thinks that there is nothing better than Misaki in sexy black underwear. He is known for being the perverted member of the trio and likes "erotic things".
Ryūnosuke was a delinquent in Seisen Middle School alongside Shirokawa, and was often seen with the latter, not only when fighting but when relaxing with the other delinquents as well, showing that the two were already good friends in middle school. At some point, he and Naoya saved Gouki Aratake from being bullied.
Ryūnosuke appears alongside the rest of the idiot trio at the gates to Seika High where they are lectured by Misaki about proper dress code, with Ryūnosuke specifically warned about his jacket. Later on, the three of them are found once again by Misaki as they litter, having once again neglected the proper dress code. Ryūnosuke watches as Naoya refuses, when asked by Misaki, to remove his earrings and has them promptly ripped from his ears, much to his shock and pain.
That evening, in the next town over, Ryūnosuke and the others find Misaki in her maid costume outside Maid Latte. Recognizing her and wishing to pay her back, Ryūnosuke takes his phone in order to snap photos while Naoya grabs her wrist, with Misaki too weak to fight back. Before anything more happens, Takumi Usui shows up and forces Ryūnosuke and the others to leave. The next day, after Misaki's recovery, Ryūnosuke and the others are seen in Maid Latte staring at her as she works, having become her fans.
Due to his discovery of Misaki's job, Ryūnosuke develops an affection for seeing her work and regularly begins visiting Maid Latte. While visiting one day, Ryūnosuke and the others order the omurice and continue to visit from then onward.
During one visit, the trio, having earned enough points to challenge Misa for a chance to take a picture with her, enters the café with Naoya taking the game himself. Ryūnosuke watches as Naoya takes up the challenge to beat Misa in a card game called "Speed". However, Naoya is quickly outwitted and defeated by Misa, who doesn't break a sweat. Saddened at not getting a photo, Ryūnosuke begins sobbing alongside his friends. However, Satsuki Hyōdō's encouragement makes him and the others regain their resolve and create a plan to earn more points and issue another challenge to Misa in the future.
In the last chapter, he is working at part-time jobs and is currently dating Erika.
- "Misa-chan! I'm out of reasons. Please be my personal maid!"
- He is the eldest of the Idiot Trio.
- According to the character profile in the manga:
- He is specialized in sewing.
- He likes anything ecchi.
- Tenryū means "dragon of mediate".
- Kurosaki means "black point".
- Ryūnosuke is in class 3-6.
|Misaki Ayuzawa • Sōtarō Kanō • Shōichirō Yukimura • Takashi Hagimoto • Kenji Sawa • Kiyomasa Katada • Hayase Kōta • Yūta Utsumi • Bunta Kosugi|
|Naoya Shirokawa • Ryūnosuke Kurosaki • Ikuto Sarashina|
|Takumi Usui • Hinata Shintani • Shizuko Kaga • Sakura Hanazono • Suzuna Ayuzawa • Yumeyama Brothers • Takezawa • Gonda • Masaru Gōda • Hideki Suzuki|