Saku is a VTuber that streams on Twitch most days of the week and uploads edited down streams and unedited vods onto YouTube on two separate channels. While he is a bit of a variety streamer, the variety doesn't really show its face unless he's doing a special event like a subathon. Otherwise, he has several games series most of which are visual novels.
Lore is currently [REDACTED] or otherwise a WIP, currently in the process of being written to be turned into a one-shot comic. Channel lore is that Saku started off as a jackalope, then a sea bunny, then into humanoid character designs. The sea bunny and otherwise bunny themes have stuck to the channel but it's unknown at this time how much this will be reflected in the actual lore of the character.