The story begins with Kudo Manabi, a high school student who secretly works as a popular photographer under the alias "MANA" on social media. He receives requests from cosplayers and companies, negotiating prices for his services. His childhood friend, Yano Sakuya, a devoted otaku, often accompanies him and asks for autographs.
Manabi is preparing for a photoshoot with a rising cosplayer named "Towano Sei," known for her stunning beauty. He heads to his private studio, a well-equipped space he had his parents build. The requested theme is a "ruined" atmosphere for Sei's cosplay of a succubus character from a dark fantasy anime.
Upon Sei's arrival, Manabi is shocked to discover that Towano Sei is actually his classmate, Towada Hijiri. Hijiri, known as the "saint" of their school for her kindness and academic prowess, is mortified, as her cosplay activities are a secret she keeps from everyone. Manabi, realizing the potential scandal, agrees not to report her, provided she keeps their arrangement secret as well. He also proposes a deal: instead of payment, Sei will allow him to use her photos for self-promotion, crediting "MANA." Sei readily accepts, impressed by his photography skills.
Their unusual partnership begins. Hijiri, now referred to as Sei by Manabi, starts assisting him at his studio, helping with preparations and even acting as a makeshift assistant. She expresses her passion for cosplay and her desire to be photographed by Manabi. During their sessions, Sei's dual nature is evident: the demure schoolgirl and the confident, alluring cosplayer.
One weekend, Manabi and Sei go grocery shopping together. To maintain secrecy, Sei disguises herself with a wig and colored contacts, adopting a foreign persona. They are nearly discovered by Hijiri's friend, Hatsushima Ei, who notes Sei's resemblance to Hijiri. Manabi narrowly avoids exposure by emphasizing their lack of connection at school.
Back at the studio, Sei prepares breakfast for Manabi, showcasing her domestic skills. She expresses her dedication to his well-being, seeing herself as his assistant. Manabi, in turn, acknowledges her efforts and the importance of his health for his work. Sei's dedication to Manabi grows, fueled by her admiration for his passion and talent as a photographer. She finds joy in being photographed by him and in her role as his assistant, developing a warm affection for him. The chapters conclude with their unique relationship solidifying, built on shared secrets and a mutual passion for photography and cosplay.
