His personality is arrogant and insolent—a devilish miser who toys with both people and money—but at his core, he possesses a strong conviction and kindness, wanting to save patients who might otherwise lose their lives to misfortune. He is known for imposing 'Chance Simple' on his patients, a fateful gamble where they bet half their fortune on a coin toss. He has a small, slender build and elegant, bright silver hair. He is 41 years old. His speech is soft and charming, yet pretentious and filled with sarcasm, provocation, and French loanwords. He says things like, "I am a devil. Loved by God, you see." He was recruited to Tojo University Hospital from a heart center in the Gold Coast. He is the world's only genius cardiac surgeon capable of performing 'Direct Anastomosis,' the pinnacle of coronary artery bypass surgery. He only touches the heart itself, leaving the task of reaching the heart to others. His catchphrases include "The heart is beautiful" and "Will you move?" He views surgery as an art and loves classical music. He was invited as a candidate for the director of the planned 'Specialized Cardiac Surgery Hospital' envisioned by Professor Saeki (the hospital director), which Amagi unilaterally renamed the 'Cerisier Heart Center' (Cerisier means cherry blossom in French). The new facility is planned for a location where the sea is visible from every room. In truth, he has suffered from a severe heart condition since childhood (coronary artery stenosis with a risk of myocardial infarction) that can only be cured by Direct Anastomosis. In other words, he is dying. The reason he collected vast sums of money through Chance Simple was to fund the establishment of this center. His obsession with the center stems from his desire to create a sanctuary where even the poorest people can receive cutting-edge medical care equally. He began using Chance Simple to decide whether to operate because of the trauma of failing to save his mother during a past surgery. His parents are deceased, and his only family is his long-lost twin brother, Seishiro Tokai. He calls Director Seigo Saeki 'Monsieur.' He calls Masashi Sera 'Juno' and is fond of him for his dogged devotion to his patients.

His personality is honest and sincere; he possesses a hot-blooded, straightforward sense of justice and is a kind-hearted person who puts the patient's life first. He is often at the mercy of arrogant genius surgeons. He has an average, toned build and calm black hair. He is in his early 30s. His speech is polite and sincere, typical of a young doctor, becoming more passionate when his emotions are stirred. He is a cardiovascular surgeon at Tojo University Hospital. Years ago, he was trained as a new intern under Seishiro Tokai and has since steadily built his career. He now serves as Amagi's assistant, learning his transcendent techniques firsthand. He is called 'Juno' by Yukihiko Amagi.