v0.1 guide for the lazy:
(TL;DR 100% save at the end)
as soon as you can controll your character walk left past the first building and enter the 2nd building, the one with the basketball field inside. (arm pit licking scene starts). Follow the girls into the left room and move closer to the shower (scene continues).
exit the building and walk around the building(once you get close enough to the horse+red haired girl+dog the scene starts)
walk to the right, above the small wooden building you see a brown haired girl in the forest (use the mouse with auto pathing to get to her since its easier)
now finally enter the first main building (the one you started infront). Move up the stairs to the 1st floor and enter the girls toilet on the right side of the building.
now move back to the ground floor and enter the 1st door on the right side and walk into the principals office.
after a bunch of dialogue and the menu tutorial the actual game starts.
walk to the top right and talk to matsubo infront of the tent.
enter the small wooden building and pick up the sparkling item in the top right (pipe).
move to the left infront of the basketball building. you'll see some dirt with a small shovel beside the drinking foutain and bunichi. pick that thing up.
enter the building and then go to the shower room and interact with the sparkling symbol beside the shower.
now go to the bottom right swimming pool area and talk to anaellë.
open the menu and click next period.
walk to the left and talk to yuki and atsushi infront of the toilet.
go outside and up to the small wooden building with the pipe inside.
after the scene enter the room on the bottom left (arts room with a sparkle icon. CAREFUL YOU HAVE TO BE INSIDE THE ROOM WHEN YOU INTERACT WITH THAT THING OR THE GAME WILL SOFTLOCK).
the clay event auto skips to the next period
enter the building and go to the room on the right side (principals office) and talk to the principal, leave the room and enter the door right above and talk to ruth.
enter the main building again, go to the first floor and make a save infront of the arts room. (that's the save i've included)
enter the room and watch the ending of the game
after finishing the game auto save will start the final ayame scene.
full save for the even lazier:
my included save has all scenes unlock, used a save editor to unlock them all (game ends if you watch tapir+ayame scene).