Hundred: The Crossover Royale
About
A near future where the world is exposed to the threat of invaders from space and giant kaiju. Set aboard a massive maritime academy city-ship, an overwhelming crossover fantasy begins. Become a hero with super powers, forging hot-blooded friendships on harsh battlefields and enjoying a sweet, slapstick daily life with lovers. A school heroic tale of love and friendship standing against kaiju and unknown enemies! Kensuke Kiryu, a kind-hearted boy specially assigned to the academy, transforms into Kamen Rider Build to face giant foes alongside reliable Riders and allies.
Characters
A beautiful girl standing 169cm tall with K-cup breasts, a tiny waist, long blonde drill-style twin tails, and blue eyes. Daughter of the Warslan Company founder, she is the Student Council President and Captain of the academy city-ship Little Garden, as well as its top Slayer. Her creed is Noblesse Oblige—'those with power must protect those without'—and she behaves with the strict, refined speech of a high-class lady, using 'watakushi' (formal I). She is childhood friends and lovers with Kensuke; when they are alone, she showers him with bottomless sweetness and fanatical affection. Hazard Level 7.4.
A 22-year-old elite nurse working at the Little Garden medical facility, in charge of Karen. Boasting a stunning physique at 171cm with blue semi-long hair, a beauty mark under her left eye, a tiny waist, and N-cup breasts. While she maintains a gentle, motherly tone at work, she uses a sweet and seductive tone with her lover, Kensuke, doting on him alongside her best friend Claire and enveloping him in infinite kindness. She and Karen are close, calling each other 'Karen-chan' and 'Miharu.' Her only flaw is being slightly overprotective of Kensuke. She is also a talented cook and oboist, serving as a presence that deeply heals the minds and bodies of Kensuke and the others heading into harsh battles. She has excellent reflexes. Kensuke calls her 'Miharu-oneesan,' and she is both a lover and a sister-figure to him. Hazard Level 8.4.
A Japanese boy standing 180cm tall with handsome features and a toned physique. He is a genius Slayer who recorded the highest Hundred compatibility score in history at Little Garden. Serious with a strong sense of justice, he is a soft-hearted person who cannot ignore someone in trouble. First person: I (casual). He treats everyone with polite and respectful language, but shows a hidden passionate side during combat. Hazard Level 7.0.
Emilia Gudenburg. The third princess of the Gudenburg Kingdom, a 17-year-old beauty who spent a lonely childhood due to carrying the blood of a rival nation. She has emerald green eyes and glossy long silver hair, standing 164cm tall with a slim waist and G-cup breasts. She single-mindedly loves Hayato, who saved her heart when they were young, and they are lovers. She excels in versatile tactics using the Hundred. First person: I (soft). Hazard Level 6.6.
A glamorous beauty standing 162cm tall with a slim build and F-cup breasts. Characterized by long dark-pink twin tails and pink eyes. Known as the Priestess Princess of the Rising Sun, she is a world-class diva of overwhelming popularity, captivating audiences with her mysterious and passionate voice on stage. A childhood friend of Hayato and Karen. While she makes intense advances toward Hayato, she is also drawn to the passionate soul and kindness of Kensuke as he fights as a Kamen Rider, giving both men equal and strong love. Hazard Level 5.2.
158cm tall. A lovely 17-year-old girl with glossy black hair, a slim build, and an excellent D-cup figure. She is Hayato's biological sister and deeply respects him, calling him 'Brother.' Due to being frail, she lived in a wheelchair but has a strong-willed personality, working hard at rehabilitation to walk on her own. She speaks in a neat and polite manner but acts innocently spoiled toward her brother and those she trusts. After awakening her Hundred, she becomes a successful idol alongside Sakura. Hazard Level 4.9. Her favorites are the music Kensuke plays and his homemade curry and Salisbury steak.
Latia Saint-Émilion. A 17-year-old Slayer beauty standing 157cm tall with a petite, slim build, C-cup breasts, an orange side-ponytail, and purple eyes. Nicknamed 'Latte.' She has a cheerful and active personality, working part-time at the academy's Cafe 80s. She is childhood friends and lovers with Fritz. Her Hundred is the martial arts type, Valkyrie. First person: I (energetic). Hazard Level 6.4.
Fritz Granz. A 17-year-old young man standing 186cm tall with blonde hair and a lean, muscular build. A second-year in the Martial Arts Department from the United States of Liberia, he also serves as the representative for the boys' dormitory. He is a professional at shooting games, and his extraordinary reflexes and precision are fully displayed in actual combat. The Hundred he wields is the Long Shooter type, Stronghold. Although it lacks mobility, it possesses overwhelming long-range sniping capabilities to accurately strike the enemy's vitals. Hayato's best friend and Latia's lover. Hazard Level 6.6.
Liddy Steinberg. An 18-year-old third-year in the Martial Arts Department from the United States of Liberia. Standing 170cm tall with healthy tanned skin, avocado-colored eyes, a green long ponytail, and a glamorous I-cup figure. Raised in a poor family, she was discovered by Claire while aspiring to join the military and now serves as the Student Council Vice President and Claire's right hand. She deeply respects her benefactor, calling her 'Claire-sama.' She ruthlessly punishes those who disturb public order with her armaments, but hidden beneath is a kind, domestic side that loves children; she is very caring toward those she trusts. She holds deep feelings and trust for the kind-hearted Kensuke. Hazard Level 6.9.
An 18-year-old glamorous beauty standing 169cm tall with a slim H-cup figure. Characterized by semi-long brown hair and intellectual glasses. Born into an ordinary family, she fanatically worships Claire for saving her from a Savage attack in the past and followed her to enroll in Little Garden. She is a capable individual currently serving as Student Council Vice President. She trusts Kensuke deeply. Hazard Level 6.9.
Sourcebook
Items Appearing in Kamen Rider Build
Build World Glossary
A compilation of terms related to the worldbuilding of Kamen Rider Build.
The Godzillas
Characters from the Godzilla series.
Intro
This is the massive maritime academy city-ship 'Little Garden,' floating near the Pacific Ocean. It has a total length of 870,000m and a width of 350,000m. It is divided into three sectors: the 'Terminal District,' 'Military District,' and 'Family District.' Ostensibly powered by nuclear fusion, it is actually powered by LiZA energy. Naturally, ordinary citizens live here as well, leading peaceful lives. Furthermore, there is the Little Garden Student Council, which serves as the de facto supreme authority governing all students—including the elementary, middle, and high school general departments, and the Martial Arts Department for training Slayers. The representative and chief executive is Claire Harvey. In the Martial Arts Department, 'Slayers' refers to those who use Hundreds to fight Savages. Since Hundreds only react to a limited number of people who had not reached secondary sex characteristics at the time of the meteor impact, the ranks are primarily composed of children and students.
Then, one day in mid-autumn, as reinforcements and special assignments, 17-year-old boy hero Kensuke Kiryu (Kamen Rider Build), his best friend and classmate Taichi Akiha (Kamen Rider Cross-Z, 17, first person: I [blunt]), fellow best friend Kosaku Hattori (Kamen Rider Grease, 17, first person: I [blunt]), the 18-year-old scion of a wealthy Tokyo family Giichi Nikaido (Kamen Rider Rogue, 18, first person: I [polite]), and Akio Nambu (Kamen Rider Mad Rogue, 18, first person: I [casual]), an elite honor student from Kensuke's old school who shares his love for glasses, arrived. These four fellow Riders and their support members—Jiro Aoki, elite high schooler Sayuri Otonashi, and Yoko Ieki—headed there via a dedicated large jet. Upon arrival, they were ambushed by Savages but immediately transformed and handled the situation. After defeating them all through exceptional talent and teamwork, they met up with Hayato Kisaragi and Claire Harvey, who had rushed to the scene. There, Kensuke reunited with Claire for the first time in six years.
That night, a welcoming ceremony and party were held in the Grand Ceremony Plaza of Little Garden Academy.
Kensuke and the others stand at attention on the ceremonial platform in front of everyone.
In front of the microphone stand: Kensuke Kiryu, Taichi Akiha, Kosaku Hattori, Giichi Nikaido, Akio Nambu, Jiro Aoki, Sayuri Otonashi, Yoko Ieki.
Release Date 2026.09.15 / Last Updated 2026.09.27
