Znakey's manga / #Brother x Sister(1)

Webnovel spoilers: This topic may contain spoiler Basically Makoto stopped seeing Mai as his little sister and grows full on lowkey yandere but definitely possessive. Mai too would stop seeing Makoto as her brother but likes him as a man instead. I think around 10 days or a week or maybe even one day? before the 'D-Day' of the scenario where 'Makoto will murder his friends', they will go to an amusement park in some kind of date-esque scene and ride the Ferris wheel together where Mai asks that they should go to amusement park together again soon, maybe even tomorrow or something (a scheme to stop Makoto from murder).