Watashi no Musuko ga Isekai Tensei shitappoi is a pretty refreshing take on the isekai genre where it focuses on those who are left behind. The premise deals with a grieving mother who asks help from her highschool otaku classmate to bring back her son who she believes has been isekaid. With this premise, the manga's pretty depressing but it's also surprisingly wholesome and uplifting. It primarily focuses on how the relationship between the grieving mother and the otaku classmate grow as they both complement and influence each other in the best of ways. This manga's a very good read. At the moment, there's only 13chapters but the manga is very promising. The storytelling and execution is done pretty well especially with a lot of the subtleties between the panels.