She's Adopted a High School Boy! Vol. 4 (Kodansha, 2021)

""If you're happy, I'm happy"" is the motto of the next-door neighbor who paid off Minoru Soramoto's family debt and took him in, all at no charge… Where will this exciting new life with the mysterious lady lead next?! Since moving in with the lady next door, Minoru's been living the good life. At home, he loves to see her do her sexy yoga, and she even takes care of him outside of the house when she comes his rescue during a confrontation with some scary upperclassmen… but all that changes when he receives a letter from his estranged parents. Will this spell the end for Minoru and Shiori-san's life together?!