This is the 特典 of お家に帰るまでがましまろです first limited edition.
It is an after story of primal x hearts 2. People seem to upload mashimaro but they don't have this game.
With the release of プライマルハーツ1+2パック, I was hoping it would be included but seems like only serial numbers were given out.
Hopefully someone can upload this as well.
Buying resources out of their own pockets, spending energy and effort, with almost no return so that everyone can enjoy the cultural and entertainment products of developed countries at almost zero cost walking in the dark to serve the light, they are real heroes