Rewind to Wai Tak-shun’s childhood days and Tak-shun is devastated due to his father Wai King-yan’s death. He then has mood swings and loses interest in everything. He even completely forgets about his father. For Tak-shun’s sake, his mother Tse Mei-sheung and uncle Tse Tim-sing never mention King-yan’s death.
One day, Yuka Sekiguchi who is working at a real estate company, had to take over her grandmother's house and was asked to check for a hidden closet. Due to curiosity, she looked for it and found the hidden closet where she suddenly slips back in time to Edo clueless. She then meets Ukai Denzaburo, a policeman at Minamichi Police Station, who got her involved in an investigation of a murder and asked for her advice during the investigation due to his poor reasoning skills.
Fujita Kazuyuki is an otaku who turns out to be the one carrying the Millennium Saber within. That means that he's actually Arest Horn, a legendary hero. Amore Gore, an evil organization of demons, seek the Millennium Saber in order to rule the world. Three girls, Arisu, Airi, and Akira, magically appear in Kazuyuki's life. When they transform they become the Three Musketeers of Arest Horn, and it's their duty to protect Kazuyuki until Arest Horn awakens.
This was a little while ago. Kyoto in the early 20th century, having evolved differently from the history we know today. In a world where only steam engines had advanced, the city was shrouded in smoke. A boy who lost his brother, with whom he had dreamed of the "Age of Electricity," and now lives with deep suspicion. A girl who keeps her dreams for the future and her regrets for her deceased mother hidden in her heart, now living a devout life. The boy and girl meet while seeking the secret of the "20th Century Electrical Catalog," which depicted their dreams. Surpass who you are now and break through the dreams you once had! This is the story of regeneration.
Liu Xiangxiang, trapped in a dream, is tasked with assassinating Prince Mu Chunshen in the Kingdom of Chu, with four chances before facing death by poison. Disguising herself in various roles within the prince's mansion, her attempts are repeatedly thwarted by unforeseen events. As she gets closer to Mu Chunshen, she discovers his kindness and falls in love, while uncovering the hidden truth behind her assassination mission.