Early Sasa Sanctuary
Note: This page describes a glitch, trick, or exploit. To see others, click here.
This allows you to skip the Satomi Power Orb quest and get Waterspout quickly. You can also fight Gi (aka Take) before getting the Canine Tracker. This makes the game think you've already fed one of the four dogs in Kusa Village, causing the fight with Tei to trigger after feeding only three dogs. If you avoid feeding Ko (the dog in the long cave that normally requires Vine to reach), you can feed her next to Fuse after the Tei fight, which warps Ammy into the cave, saving some time when leaving Kusa. This currently isn't used in any category, though, because NG+ Any% skips feeding the dogs entirely, and NG+ AB skips fighting Take (see https://youtu.be/GNUdUScSanU).
Right after entering the area, go right and jump up next to the rock. Do one KT up, using your second wall jump to go right towards the loading zone. Do one more KT to clear the loading zone and run up to the edge of the area.
Jump off, hold the map button and start aiming towards the origin mirror. When the background changes colour to a lighter blue, hold the direction for two more seconds, then let go. You should land directly in the main hall.
You can also land in the hallway towards the hot springs, but this is a bit more risky and should be avoided by newer runners.
If you land in the Sparrow Boss' room, simply jump down the elevator shaft. Make sure you don't land on top of the elevator, because this will soft lock the game.
Because Bufferless KTs are faster than buffered KTs you can also straight up KT over the invisible walls on the right of the entrance gate. This is only faster than the Interior Clip when using bufferless KTs.
It is possible to perform an interior clip into Sasa in NG (see https://youtu.be/fyoK2HeK3yY) by landing on a seam between two very slippery slopes along the path to the front entrance. From there, one can tackle jump over the collision and land inside the lower interior, just like NG+. The initial Seam Grip is very precise, requiring a perfectly timed gold dash jump from the in-bounds ledge, followed by a full-speed wall jump.
After the tackle jump from there, if Ammy becomes grounded but still clears the collision, one can still save the attempt by quickly holding the analogue stick to drift Ammy toward the loading zone for the front entrance of the Sasa interior, then air tackling into it before Ammy falls past it. This will place Ammy outdoors, but behind the locked gate, at which point you can simply walk back in.