Sota is Ikuno Mai's boyfriend and the train station guard. One night, Mai and Sota were sleeping in their apartment when Yui visited them. Mai woke up and told Sota that she's had a strange dream about Yui. Mai, and Sota returned to their apartment and listened to Yui's voicemail that Mai received and saved while working at a hotel. They heard Yui's breathing and then a death rattle. Sota got scared by it and turned it off. Next evening, Sota returns home from work, and sees Mai reading Kayako's diary. When she goes to the bathroom and takes a shower, he reads the diary too, gets scared, and disturbed by it, and tries to dispose of it. Next evening, Sota meets Kayako in the metro, hears her repeating her quotes from the diary, and recognizes her as it's owner. Sota follows Mai when she goes to Reo's house after meeting Kyosuke at he place where the Saeki house was. Sota questions Ena about the house and it's inhabitants and experiences her telepathic visions. He goes to the house, finds Toshio, and is strangled by him. Sota thinks he's killed him. He returns to his and Mai's apartment, sees that Kayako's diary has returned again, and tries to burn it, but is unsuccesful. Later, that evening, Mai calls him, but receives no answer. Soon, he is killed by Kayako, and Mai returns to apartment, and finds him dead. Later, Sota's ghost goes back in time, appears in a hotel just hours before his death, and walks around it to attract Mai's attention. She sees and follows him to the elevator. He enters and disappears while Mai finds it filled with Toshio's. This encounter is a reason she called him right before he died.
Mai and Sota listening to Yui's call
Sota with Kayako in the metro
Sota is lurked by Kayako at his and Mai's apartment