Xiehou Ta de Shaonu Shidai
English title: Mom, I'm Sorry
Japanese title: 邂逅她的少女时代
Type: ONA
Episodes: 18
Source: Web manga
Genres: Drama, Supernatural
Studios: Red Dog Culture House, Studio Goindol
Producers: bilibili
Duration: 17 min per ep
Rating: PG-13 - Teens 13 or older

"Mom, I'm sorry. Please don't die." When Henry realizes death is at his mother's doorstep, he strikes a deal with a lifespan dealer to give years of his own life to his ailing mother. Now, his mother is a 20-year-old college student with a full life ahead of her, and Henry devotes his remaining days to helping her live life to the fullest. But things turn complicated when his friend falls in love with her!

(Source: LINE Webtoon)