Kageyama Sora

Biodata

Feature	Details
Name	Kageyama Sora (影山空)
Alias(es)	Sora; Kageyama-kun; Mr. Kageyama
Gender	Male
Affiliation	Ryumonbuchi family; patron and supporter of the Kiyosumi High School Mahjong Club 26 181
Occupation/Role	Game designer, software developer, company owner, and National Mahjong Tournament investor 2 4
First Appearance	Chapter 2

Background / History

Sora is an established young game designer and businessman with an assistant who compiles player profiles and match data. His first major encounter with the Ryumonbuchi family introduces him to Ryumonbuchi Toka, Kunihiro Hajime, and Amae Koromo, whose supernatural-seeming Haitei Raoyue control overturns his assumptions about mahjong. 2

Rather than being discouraged by Koromo's repeated wins, Sora becomes fascinated by luck-based and ability-based mahjong. He develops an “absolute data-driven” approach to interfere with Koromo's field, allowing Toka to reach tenpai and Hajime to win despite Koromo's usual control of the table. 3

His interest in players “loved by the tiles” leads him to study at Ryumonbuchi High School and visit Kiyosumi High School. There he meets Hisa Takei and the Kiyosumi Mahjong Club, observes Saki Miyanaga's unusual style, and becomes invested in Nodoka Haramura's growth and her relationship with Saki. 4 5 8

As Kiyosumi progresses through the prefectural and National tournaments, Sora acts as a benefactor, analyst, and emotional support figure. He arranges accommodations, follows matches closely, studies opponents, and continues developing online, VR, and holographic mahjong projects alongside his tournament involvement. 35 86 95 116

Appearance

Sora is a tall, striking young man with short black hair, dark eyes, and a notably athletic build. He is stated to be 180 centimeters tall. 101 116

• Tall, upright frame; his height is given as 180 cm. 116
• Short black hair, sometimes described with loose fringe over his forehead. 101 116
• Dark eyes and sharp, refined features. 4 116
• Maintains a polished public appearance, often wearing neatly arranged white shirts or formal attire. 101 116
• Has a well-defined physique that draws frequent attention from others. 8 146

Personality

Sora is highly curious, particularly when confronted with phenomena that data alone cannot explain. Koromo's board control, Momoko's low-presence ability, shrine maiden possession, and other anomalous styles do not make him dismissive; instead, he studies them and tests how conventional analysis can respond. 2 3 47 109

He is generally calm under pressure and uses a composed, polished demeanor in public, partly because of his youth and business position. In private, he is teasing, direct, and more emotionally expressive, frequently encouraging players when they are discouraged. 38 101 110

Sora is also protective and attentive toward people close to him. He provides practical support for Kiyosumi's members, comforts them after difficult matches, and repeatedly prioritizes their preparation and well-being. However, his numerous overlapping relationships leave him struggling with guilt, responsibility, and how to handle others' feelings fairly. 35 91 125 139

Abilities & Skills

Absolute Data-Driven Mahjong

Sora's core style uses calculation, observation, and probability management to create openings against seemingly uncontrollable luck-based play.

• Toka identifies his method as “absolute data-driven play.” 3
• His play disrupts Koromo's field enough for Toka to reach tenpai and Hajime to win by ron, outcomes previously thought impossible under Koromo's control. 3
• He considers data analysis the first step in testing whether calculated probability can overcome unpredictable fate. 3
• He acknowledges that data-driven play does not automatically guarantee victory against an ability user. 3

Player and Ability Analysis

Sora rapidly identifies tendencies, weaknesses, and abnormal abilities in other players.

• Correctly recognizes that Yuki Kataoka is strongest during the East Round after watching her play. 5
• Notices Saki Miyanaga's unusual mahjong presence before fully understanding her ability. 5 11
• Deduces Toyoko Momoko's invisibility ability from her behavior and later confirms that he can perceive her even when it is active. 47 59
• Explains how Nodoka's concentrated, online-like mental state allows her to ignore ability-based interference, including Momoko's invisibility. 47
• Helps Nodoka refine her tactical judgment against an AI by identifying its deceptive discard pattern and calculation zone. 86

Technical and Business Expertise

Sora combines software knowledge with his interest in competitive mahjong.

• Works in software and is particularly sensitive to numbers and mathematical reasoning. 24
• Oversees online and holographic mahjong development and uses competitive players as trial participants. 95 116
• Organizes VR-based training that helps players adapt and improve through a new practice method. 89
• Uses his financial resources to support tournament logistics, including accommodation and meals for Kiyosumi. 35 181

Equipment / Projects

• Motorcycle — Used to bring Koromo to the prefectural tournament venue before Ryumonbuchi could be disqualified for an incomplete roster. 28
• Player dossiers and match data — Sora relies on assistant-prepared profiles and his own research when evaluating players. 2 4 99
• Holographic Mahjong Project — A development project for which he organizes trial sessions with selected players. 95
• VR training system — Used during training to help players develop through simulated mahjong practice. 89

Relationships

• Ryumonbuchi Toka — His cousin and frequent sparring partner. Their teasing, competitive dynamic develops into an intimate relationship, though Toka remains protective of both Koromo and her family. 3 19 161 164
• Amae Koromo — His cousin and the first ability-based player to deeply fascinate him. Koromo is emotionally dependent on Sora outside mahjong, while he consistently reassures and protects her. 2 50 51 64
• Haramura Nodoka — A central romantic partner and one of the players Sora most actively supports. He promises to help resolve her conflict with Saki and continues encouraging her throughout major tournaments. 7 47 181
• Miyanaga Saki — Sora notices her unusual potential early, helps her confront her reluctance toward mahjong, and later shares a close, trusting relationship with her. 5 8 184
• Kataoka Yuki — A Kiyosumi player whom Sora analyzes, tutors, comforts, and encourages after difficult matches. 24 38 70 110
• Takei Hisa — Kiyosumi's captain and a trusted collaborator. Sora respects her ability to cultivate each member's potential, while Hisa holds him accountable when his personal relationships affect team training. 29 91
• Someya Mako — A Kiyosumi member whose feelings for Sora become explicit when she confesses to him; Sora promises to consider those feelings after the tournament. 95
• Toyoko Momoko — Sora is the first person wholly unaffected by her low-presence ability, giving Momoko the rare feeling of being truly noticed. 59 171
• Jindai Komaki — A shrine maiden and Child Loved by the Tiles whom Sora first meets at a Ryumonbuchi family banquet. Their relationship becomes personally significant amid Komaki's unexplained spiritual condition. 64 65 109
• Ishido Kasumi — An Eisu shrine maiden whom Sora supports during the Kagoshima amusement-park arc; their bond develops through shared experiences and mutual protection. 131 132 170
• Kainou Yoshiko — A professional mahjong player and former security-team leader with whom Sora discusses mahjong, business records, and their respective backgrounds. 116 118

Story Role / Major Arcs

• Ryumonbuchi Encounter — Meets Toka, Hajime, and Koromo; Koromo's Haitei Raoyue ability drives Sora to investigate luck-based mahjong. 2 3
• Kiyosumi Introduction — Visits Kiyosumi High School, meets its Mahjong Club, and becomes involved in Nodoka and Saki's personal and competitive development. 4 5 8
• Prefectural Tournament Support — Supports Kiyosumi and Ryumonbuchi at the preliminaries, provides accommodations, observes player abilities, and helps players recover from difficult rounds. 26 35 38 47
• Mahjong Technology Development — Expands his involvement beyond spectating through VR training, holographic mahjong trials, and tactical analysis. 86 89 95
• National Tournament — Studies prominent schools and their ability users, supports Kiyosumi from the sidelines, and becomes entangled with Eisu's shrine maidens and other competitors. 99 109 119 120
• Kagoshima and Return to Tokyo — Leaves Kagoshima after forming new bonds, then returns to Tokyo to resume responsibility for Kiyosumi's National Championship preparations. 139
• Ryumonbuchi Family Return — Returns for his grandfather's birthday, reconnecting with Toka and reaffirming his connection to the Ryumonbuchi family. 160 161

Notable Quotes

“No, this is just the first step. I want to know, when calculable probability collides with unpredictable fate... who exactly is the master of the game?”
— Kageyama Sora 3

“If you always wait, you will miss out on many things.”
— Kageyama Sora 8