An accident sends Bai Ziyu traveling to the early 20th century in Neon. After nineteen years of silence, he suddenly awakens his past life memories! Then, he realizes something's amiss. He's a third-year student at Maple Academy, and his deskmate is named Marina Kamisaki. Soon, her mother is planning to marry a teacher named Kozo Akizuki. And that's not the end of it: another classmate, a yellow-haired man named Kazuhiko Amemiya, is rumored to have a new stepmother for him. Oh my god, this is a shabby anime-inspired world. Just then, the time-traveling system—a standard feature for time travelers—makes its grand entrance. Saving the goddesses with a beauty rating of over 90 from the original show grants rescue points to empower oneself. With the system's help, Bai Ziyu races on to save the goddesses and annihilate the Minotaur. (Note: This is the protagonist's past life awakening, not a soul-transmigration.)

Qiubai has traveled to a world where inner and outer worlds merge. Growing up, he's surrounded by characters he's "familiar" with. There's Akizuki Airi, Akizuki Marina, Shiina Chizuru, Mashiro Chisato, Hoshizuki Kaede, Hoshizuki Suzu, Nanao Akane... and his two younger sisters, Mikan Yuuki and Kasugano Sora, who live with him. Mikan is young, but capable, mature, and energetic, taking care of the housework daily, making her a worry-free existence. Sora is slightly older, but aloof and tsundere, with a slightly frail constitution. She stays at home every day, a worrying prospect. When Qiubai turns 18, the system officially activates! Kuze Akibai: What? Just coming of age, I have to become a male succubus in the inner and outer worlds? And I even have the ability to stop time!