In the game, you need to find a total of 55 squirrel pictures to unlock a side case called Big Squirrels Don't Cry, which will lead you to the final graffiti. Each squirrel picture you examine will hint at what you need to do to find the reward.
On this page, you will find pictures locations around Seiryo High school. The rest of the collectibles are listed on separate pages of the guide, divided by districts. You can discover the pictures numbered between 2 and 55 in any order.
The 1st picture of a squirrel is on the wall of Seiryo High school. After talking to the girl, you will unlock searching for the remaining graffiti.
The 2nd picture is on the wall by Seiryo High school.
Using the Noise Amp, examine the next picture on the bridge pillar.
The squirrel will point out the location of the reward. Use the drone to pick up Book of the Ardent.