This app is brought to you by the biggest Photo Studio club in Japan which deals in shichigosan [Japanese Culture]
Shichigosan is a traditional event in Japanese culture held for kids of age 7 5 and 3 hence the app name 753.
With this app you can immediately find the closest photo studio closest to your current location [ within Japan]. Costumes can also be searched by color, type [Sports, dress,etc]. These studios are spread throughout the Japan so you are surely going to find a shop near you!
Its free and convenient app for your cute kids!