The 2nd Chapter continues the story of Ryo Takatsuki and his companions' quest to discover the secret of the mysterious A.R.M.S. they all possess and what the future may hold for them. They now know where the answers lie but to get to them, they must fight a desperate fight of survival against a powerful military corporation that wants their secrets no matter what the cost. (Source: AniDB)

Dismissed as a hopeless loser by those around him, 27-year-old Arata Kaizaki bounces around from one job to another after quitting his first company. His unremarkable existence takes a sharp turn when he meets Ryou Yoake, a member of the ReLife Research Institute, who offers Arata the opportunity to change his life for the better with the help of a mysterious pill. Taking it without a second thought, Arata awakens the next day to find that his appearance has reverted to that of a 17-year-old. Arata soon learns that he is now the subject of a unique experiment and must attend high school as a transfer student for one year. Though he initially believes it will be a cinch due to his superior life experience, Arata is proven horribly wrong on his first day: he flunks all his tests, is completely out of shape, and can't keep up with the new school policies that have cropped up in the last 10 years. Furthermore, Ryou has been assigned to observe him, bringing Arata endless annoyance. ReLIFE follows Arata's struggle to adjust to his hectic new lifestyle and avoid repeating his past mistakes, all while slowly discovering more about his fellow classmates. [Written by MAL Rewrite]

After reliving the life of a high school student through the ReLIFE experiment, 27-year-old Arata Kaizaki cannot believe how quickly it has changed him. He has begun to see the world through a different perspective that he had completely forgotten as an adult. He has made friends and formed deep relationships with each one of them. However his support, Ryou Yoake, reminds him that the experiment is all an illusion; after his experiment ends, he will be forgotten by all of them. The experiment of another ReLIFE subject is also coming to an end. After spending two years with ReLIFE, Chizuru Hishiro has developed into a more open, more thoughtful person than she could have ever imagined. She has met people who have changed her life, her perspective, and ultimately her. However, now that their ReLIFE is coming to an end, will they be able to let go of the memories they have made? [Written by MAL Rewrite]

Kazuya Kinoshita is a 20-year-old college student who has a wonderful girlfriend: the bright and sunny Mami Nanami. But suddenly, he doesn't. Without warning, Mami breaks up with him, leaving him utterly heartbroken and lonely. Seeking to soothe the pain, he hires a rental girlfriend through an online app. His partner is Chizuru Mizuhara, who through her unparalleled beauty and cute demeanor, manages to gain Kazuya's affection. But after reading similar experiences other customers had had with Chizuru, Kazuya believes her warm smile and caring personality were all just an act to toy with his heart, and he rates her poorly. Aggravated, Chizuru lambastes him for his shameless hypocrisy, revealing her true pert and hot-tempered self. This one-sided exchange is cut short, however, when Kazuya finds out that his grandmother has collapsed. They dash toward the hospital and find Kazuya's grandmother already in good condition. Baffled by Chizuru's presence, she asks who this girl might be. On impulse, Kazuya promptly declares that they are lovers, forcing Chizuru to play the part. But with Kazuya still hung up on his previous relationship with Mami, how long can this difficult client and reluctant rental girlfriend keep up their act? [Written by MAL Rewrite]