Osamu Matsumoto (松本 修 Matsumoto Osamu?) is a character in the Vivy: Fluorite Eye's Song series. He is the creator of the AI Matsumoto and sends him back to Vivy (a.k.a Diva) 100 years in the past in order to save humanity.
In 100 years in the future - 2161, AI have gone rouge and murdered humans indiscriminately. Inside the Arayashiki Tower, wounded Osamu is moving to the communication room and lock himself inside, where he initiate Project Singularity. As the AIs hunting for him trying to break through the door, Osamu utters few last words before he sends his AI back in time and gets shot.
As the series progresses, young Osamu first appears in 2126 in the museum where Diva is archived, going on a school trip with his class.
He takes a liking to Diva and visits her regularly even into his adult years.