In to Yuu no Jikenbo Mizu Shimi

In and Yuu, who become brothers due to certain circumstances, encounter a bizarre incident. In finds Yuu, who has become unable to speak due to a past incident and has a weak reaction, annoying. One day, he receives news that Yuu has been trapped in an elevator at the place where he works part-time... The story depicts the mysterious spirits surrounding the two. (Source: Natalie, translated)