After selecting a character and stats, the next screen will have a cheat button. Then, activate the following cheats by entering the corresponding codes:

CHEAT FUNCTION -  CHEAT CODE
The Springs Are Hell - hellissprings
Start with $250,000 - moneygrowsontrees
Play as Naru - naruhaseyes
Insane conversations - sofarsogood
Shinobu dress up game - rainbowsrgood
Motoko dress up game - motokoismotoko
Secret movie - eva4hidden
All moves - allyourmoves
All stats are 100 - theincredibleyou
Mutsune dress up game - smashwatermelons
Random credits - randomamv
Girls walk around with less clothing - crazygirlmot

Find the following people by searching the corresponding clickable location:

PEOPLE - LOCATION
Stalker - Outside of teahouse.
Screaming Man - Lounge.
Rei - Stair hallway.
Shinobu - Shinobu's room.
Mitsune - Mitsune's room.
Asuka - Keitaro's room.
Sadako - Keitaro's room.
Shinobu - Dining room.
Tsuruko - East Town.
Sachiel - Left of bridge.
Hyatt - Kitchen.
Excel - Kitchen.
Naru/Shinobu Hybrid - West Town.
Amara - Training Center.
Kanako - Tokyo University.