: In the men's restroom, use a sponge and detergent (found in the women's restroom) to wipe away a stain, revealing the safe code: . This grants you bolt cutters. : The final door requires the code , which translates to Essential Survival Tips Item Management
: Pay attention to the chalkboards; they provide variables for the final door code. Light Switch Puzzle Abyss School
To understand Abyss School , you must read the collectible "Sealed Notes" scattered throughout the levels. These diaries belong to students from the class of 1997—a generation before Yuna’s time. : In the men's restroom, use a sponge