| 柏崎 天馬|
|Job||Chairman of St. Chronica Academy|
|Japanese Voice||Ryōtarō Okiayu|
|English Voice||Brandon Potter|
|Novel Debut||Volume 3|
|Anime Debut||Episode 9|
Tenma "Pegasus" Kashiwazaki was born from the famed and noble Kashiwazaki lineage, and the eldest son and heir to the family. Pegasus' great-grandfather was the founder of St. Chronica's Academy, establishing its position as a prestigious all-girls school with the position of chairman being passed to the next head of the Kashiwazaki family. With his father as the current chairman of the aforementioned school, Pegasus was next in line to become its successor.
In his youth, Pegasus was a known prodigy excelling in academics, sports (track and field) and even appearance, garnering attention from many people and peers alike. Because of the many girl fanatics fawning over him, Pegasus saw this as a nuisance and thus enrolled in an all-boys school - Uguisuyama Private High School - where he met fellow classmate Hayato Hasegawa, who constantly tried to befriend him whereas a conservative Pegasus rather found the latter a bother. He was placed in class 2-4.
However, as the two bonded frequently while bathing, Pegasus began to see Hayato as a new light and started to take him seriously. After Hayato began wanting a girlfriend, Pegasus contacted Noel Redfield, a British exchange student and student council president of St. Chronica's Academy and arranged a mixer where Pegasus made a light argument with Airi Aaron, a fellow British companion of Noel's. Thereafter, while Hayato and Airi became lovers, Pegasus and Noel engaged in a secret relationship until it ended when Noel returned to England.
A year later Pegasus graduated from high school as he became attached to Hayato - becoming best-friends. Years later Pegasus met his fiancee and the two had a daughter named Sena, whereas he had set up an arranged marriage with the son of his best friend, Kodaka for the future. Eventually Pegasus became the chairman of St. Chronica's Academy and transformed the school into a more lax and co-ed one - an intention originally proposed by Noel in the past.
Suddenly, Pegasus became stricken by the death of his old friend, Airi. During the funeral, while Pegasus acted emotional, Hayato instead warned Pegasus of not waking the young sleeping Kobato lying in his arms. Met by a strong willed Hayato, Pegasus assured him of ever relying on the latter for anything and reminded him of the friendship they once shared.
Nearly a decade later, Pegasus met her step-daughter, Stella and the latter stayed at Pegasus' mansion acting as a steward while not letting Sena know of their half-sibling relationship.
Afterwards Pegasus enrolled both Kodaka and Kobato into his academy under the request of Hayato.
During the hot summer season, Pegasus unwittingly invites both Kodaka and Kobato into his estate. As the siblings arrive there, Pegasus introduces himself to the two and to his house while Stella embarrasses him of not introducing his name and telling Kodaka his given name, much to Pegasus' vexation. Afterwards, Pegasus leads his guests to his dinner table.
During dinner, Kodaka presents a gift to the Kashiwazaki's - jars of delicious spices. Thereafter Pegasus made blatant insults towards Hayato for his carelessness and for being irresponsible of taking care of his children, causing Kodaka to loudly retort back.
That evening Pegasus had Kodaka and Kobato make an overnight stay at his house. After introducing them to their rooms, Kodaka and Hayato share a drink and eventually Pegasus becomes drunk while telling Kodaka old stories of him and his father in the past albeit incomprehensibly. Pegasus subsequently falls into deep sleep.
The next day Pegasus, along with Sena, see the two siblings off with Pegasus leaving a message for Kodaka of taking care of Sena. As a reply, Kodaka agrees and teases Pegasus by calling him by his given name and staggers away, much to Pegasus' anger.
As Sena invites Kodaka over to her house for a study session, Pegasus again welcomes Kodaka as he arrives at the mansion. As Sena comes to greet Kodaka, Pegasus leaves the two as Sena asks her father if he has anything more to discuss with Kodaka, knowing that her father has always been asking her about him. Pegasus brushes the aforementioned under the pretense that he is only looking after Hayato's children.
Trip to Yokoshima WonderlandEdit
One night, Pegasus hands Sena a group ticket for Yokoshima Wonderland, which Sena uses to impress Kobato. Afterwards, a drunk Pegasus calls Hayato in regards to Sena and Kodaka's planned marriage.
In the midst of preparations for the annual school festival, Pegasus meets Kodaka. Pegasus converses with Kodaka in regards to the lively atmosphere of the school in preparation for the festival and the implication of Sena and Kodaka's relationship. When he clarifies to Pegasus that he and Sena aren't dating, Pegasus dashes off, shocked and in disbelief of the outcome.
Trip to the ski resortEdit
With the Neighbor's Club and the Student Council in a joint visit to a ski resort, Pegasus acts as the chauffeur to transport the students to their destination. While en route, Pegasus and Kodaka had a conservation about the former's past - including his popularity with the females and his ways of finding happiness - and his approval of Stella's lover. Pegasus then contemplated on the fact that cherishing and protecting someone was a foolish act, much to Kodaka's bewilderment. After a roundabout chatter with Kodaka of Pegasus' moments with Hayato, the group eventually reaches the ski resort.
At the resort, Pegasus was Kodaka's roommate and the two constantly had baths together, where they bond and reminisce.