An idol who lives and breathes his hobby, gambling, and treats his life no different than one of those gambles. He used to perform as part of a duo with Niki Shiina. Though a cheerful and generous individual, there are times he can be not only wasteful, but downright tyrannical. He is Hiiro Amagi's older brother. He likes to test his luck. With a voice that's mischievous, as if he were playing some game, Rinne's performances are powerful and larger than life.
Rinne is a fairly tall man with pale skin and cyan eyes. His hair is unruly and long, and often kept back with a black bandana with a white stripe.
His Crazy:B attire consists of a white jacket with red, black and yellow accents, worn over a white t-shirt containing a black honeycomb pattern atop a grey square and red accents at the hem and collar. He wears a chunky gold necklace with a round medallion around his neck, and has plenty of accessories on his hands and wrists. His pants are black, held up with a gold chain belt. There are white rings all down the front of the pants, and a white and yellow stripe on the outer side of both legs. He wears black lace-up shoes with yellow soles, laces and accents. White socks can sometimes be seen under the shoes.
Rinne's casual attire consists of a black t-shirt and pale blue ripped jeans. A white jacket is tied around his waist and there is a silver dog tag around his neck. He also wears a black watch and a white bracelet on his left wrist, and a silver ring on his right index finger. Rinne has small black earrings.
Rinne is lazy and freeloads off others, often wanting to play games, gamble, and have fun with people, and avoids responsibility whenever possible, including unit practice. Treating his life "like it's a game," or more famously, a gamble. He makes rash decisions for himself and his unit, and more than willing to pull others with him. He refuses to take small steps and instead takes the risk without question, as it's "fun" for him, even at the cost of everything around him crumbling. He rarely listens to others and almost never follows orders, considered crazy or chaotic by others.
Despite his behavior, he cares about the people around him under his risk-taking facade and treasures them and his unit dearly, though he mostly shows it in situations where he takes the unit seriously. When he's in a tight position, he opts to destroy or sacrifice himself for others, no matter how severe it is, under another instance of his risky behavior. He has instances where he doesn't want to be perceived as weak for showing how he really feels, as that was how he grew up to believe.
During his youth, in his village, he was more formal, serious, and stuck to whatever was in front of him, as that was what he grew to act as the next chief. That behavior would mostly stick with him until he was used to city life.
The first character in Rinne's first name, 燐, means phosphorus, which is associated with phosphorescence, Hell, and ghostly creatures. The second character, 音, means "sound". The name itself sounds like the word 輪廻 (rinne), which is the Buddhist cycle of continuous death and rebirth, involving karma. The kanji in Rinne's surname, 天城, can be translated as "Heaven's Castle".
- He was raised to be the future village leader of his hometown, which has created conflict with his younger brother Hiiro Amagi.
- He has never attended a formal school and underwent extensive training to become the future leader of his village instead of a regular school education.
- During the !! Main Story, Rinne has a shared ES dorm room with the rest of Crazy:B. However, similarly to the rest of Crazy:B, Rinne usually stays elsewhere; he usually stays over at Niki's apartment. It's currently unclear whether he spends more time at Niki's apartment or his new dorm room after the !! Main Story.
- According to a 4gamer interview with Akira, Rinne's character archetype is "a high-rolling gambler" (燐音がギャンブラーで).
- Rinne met Niki when he was 17 and Niki was 14, and the two have stayed together ever since.
- Rinne openly antagonizes and criticizes Ensemble Square despite being a part of it. This is heavily featured in the !! Main Story.
- He helps out at the Bee Hive night club sometimes, which gives Crazy:B opportunities to perform there.
- He's skilled at martial arts. 
- Rinne, a frequent gambler, often blames things on his luck. He has several catchphrases related to feeling lucky or like "Lady Luck" is on his side.
Voice Actor Comment
"Rinne-kun isn't close to any of the roles I've played up until now, he's the first type of boy like this I've met. At the audition, I was really worried. "But this was a win!" so to speak, and I could say that with all my heart, so I could play the role freely. Rinne-kun! With you, I won this gamble! So then, onto the next game together!"
|Crazy:B||Rinne Amagi • HiMERU • Kohaku Oukawa • Niki Shiina|