(After the chapter 1 motive video for makoto ended )
Makoto desperately states 'I have to get out of here. I have to get out, right now! I need to make sure everyone's safe'
saiyaka overheard him and inquired 'makoto? make sure who's safe?'
Makoto decided 'i need to come clean about this! ok saiyaka this is the video with my motive on it watch carefully and you'll see who i was worried about ' (after the video ended a second time)
Saiyaka is extremely traumatized
'that's horrible! that bear made it look like he had killed your parents and sister!' so she decided to become makoto's accomplice in killing toko Fukawa and take the blame allowing makoto to leave to check on his parents and sister
the end
(Author's note toko fukawa is a character who i didn't like because her self loathing personality got old fast. also she's the ultimate literary girl. Makoto is the ultimate lucky student until in the original timeline kyoko gave him the unofficial title ultimate hope. Also in the old timeline, ultimate j pop sayaka maizono did see the motive video about herself and was so freaked out by it she didn't let makoto explain what he saw, resulting in her planning to blame makoto had she succeeded in killing ultimate baseball star leon kuwata. so by having makoto show her his footage before she has a chance to see her own, I eliminated that possibility from the timeline. Also monokuma is a sadistic panda who gets off on performing executions, so he provides motives in the danganronpa games to get the characters killing a maximum of 2 people per chapter)