http://www.mangago.zone/read-manga/the_titan_s_bride/uu/ibx_chapter-38/pg-26/ Im not sure who's hand was that but to me it seemed like Kouichi's mom because his mom obviously would want him to be happy and be with someone he loves and then her spirit helped Kouichi. I immediately thought of Kouichi's mom cuz in the next 2-3 pages after that one, it shows that the spirit is a female and had almost the same hair length as Kouichi's mom
http://www.mangago.zone/read-manga/the_titan_s_bride/uu/ibx_chapter-38/pg-26/
Im not sure who's hand was that but to me it seemed like Kouichi's mom because his mom obviously would want him to be happy and be with someone he loves and then her spirit helped Kouichi. I immediately thought of Kouichi's mom cuz in the next 2-3 pages after that one, it shows that the spirit is a female and had almost the same hair length as Kouichi's mom