So since no one else is writing one and people are getting stuck, and I'm a bit stuck myself... This is a guide based on what I've found so far. If someone else has the answers I don't have, please share.
The main game is like a game and a half depending on whether you have Keiko get a makeover at the beginning or not. If she doesn't get a makeover, you get a short game that ends with her being the school's cum dump. If you have Keiko get a makeover, you go through the main game (tip: you don't actually have to greet to everyone in the village). I recommend at the first chance you get, go to the =F= convenience store/supermarket in the Station area and pick your speed for 10 bucks. Ninja Shoes are faster than Running Shoes.
1) Find your Classmates: You can find the students in these locations:
- Behind the school - Grab the ID from the black bag in the school's foyer first, then go north between the pool and main building.
- Village - There is a building just north of Keiko's home with a blue car. One of the students is in there.
- Mountain Road - One of the brats is in the building on the west side of Mountain Road.
- Wooden Shack - First talk to the bald guy in the corner on the west side of the Main Road, he'll tell you about a possible student in a shack. Then go to the Wooden Shack on the east side of the Mountain Road.
- Mountain Golden Statue - First talk to the weirdo in the building on the southwest side of the Mountain area. Then go to the northeast peak of the mountain to the golden statue.
- Station - The last brat is in front of the convenience store/supermarket.
Once all of the brats have been found (you don't have to find Keiko's sister), you can now talk to the teacher and end the game. I'm not 100% certain on the conditions, so these are my best guesses for the endings.
- If you haven't done anything to raise Keiko's boldness, you will get the pure ending.
- If Keiko's done some lewd things, you can get an embarrassed ending when she learns she's been fooled.
- If Keiko's had sex or has high boldness, she becomes the school's preggo. This is the only pregnant image in the whole game that I've found so far. So anyone with a pregnancy fetish, heads up, you'll be disappointed.
- If you maximized Keiko's boldness and looked in her mirror, then go talk to the teacher, you get a 4th ending. I think someone said this was the true ending. I honestly don't know.
2) Key/Map: This is a quest that begins with finding a Stick in a chest in the school yard. Go to the Main Road, one of the brats gives you a Ticket for the stick.
- Give the Ticket to a guy on the north side of the Station area. He will give you a GPS Transmitter.
- Hand the GPS to the police officer in the building southeast of the Village. He will give you Brass Knuckles.
- Find the kid in one of the caves of the Mountain area. He will give you a Protein Shake.
- Give the Shake to the jumping guy on the Main Road. He will give you a Wanted Poster.
- Look for a guy hiding on the west side of the Station area, next to a dumpster on the left hand side of the restaurant. He will give you the Map.
- YOU DO NOT NEED TO COMPLETE THE GAME OR TALK TO THE GUY IN THE TENT NEXT TO KIRI'S SHOP. Go the Wooden Shack on the east side of the Mountain Road, you will find two chests, one with the Hypnosis Drug, and the other with a Power Drill. Use the Power Drill on the rocks on the northwest peak of the mountain and get the treasure from the blue statue. It will give you more than enough money to buy all of the items in the massage tent on the Mountain Road.
- Edit - Based on Neighzorr's post (and a few others), the Hynosis Drug does nothing for English Version players.
3) Yutaka - Remember she is wearing a yellow shirt, that helps make her stand out from the rest of the brats in the game.
- You will first find her in the school yard, but you need to talk to the boy next to her.
- You can next find her in the center of the main Village just south of a building with a green roof, just northeast of Kiri's shop.
- She is now eating ice cream on the Main Road, sitting next to the guy in a green shirt.
- Yutaka goes to the plant house on the east side of the Main Village next, the building just north of the police station.
- Now she is in the restaurant by the Station.
- She goes to the Mayor's garden/pool on the northeast side of the Main Village.
- Yutaka's last location is in the hole in front of the school.
After getting Yutaka to return to school, you can talk to Aya (mother) for Aya's ending.
4) Kiri - After finding the first student behind the school, you will see Kiri leaving the main building.
- Go to the playground in the main village and talk to the kid on the bench.
- Next, go to the Station area, you will see Kiri in front of two guys jumping and whispering.
- Walk in front of Kiri's store.
- You will next find Kiri in front of the easternmost cave in the Mountain area.
I don't think there are anymore Kiri events after this. If I ever find any, I'll edit them in later.
5) - Edit - Yutaka Battle - From Morello112 - You have to complete the game and get Keiko's sister to return to school to get this event! After talking to the teacher to end the game, Keiko returns home. Go back to school and talk to Yutaka in the classroom. Yutaka can one-shot Keiko if she is not strong enough, even if you've bought the Invincible Love Wand and Global Barrier. Make Keiko stronger by increasing her boldness. You will also need at least 3 Aya's Voice to beat Yutaka (used as items). Yutaka will give you a key, which unlocks both crystal paths in the Mountain area. One is a room that lets you replay all scenes. The other has a fairy that lets you view all 3 of the main endings.
6) Keiko Black tells us everything that was going on with Kiri, everything begins to make sense. It's pretty much linear, except for one choice you get to make at the end that determines the ending. Save the game when Kiri wakes up in the Wooden Shack with 3 guys around her if you don't want to replay everything.
