The manga is official and has a game tie-in where buying the upcoming first volume will entitle you to a serial code for Ping-pong Chrysanthemum (the preparation of that volume is probably the reason there wasn't a chapter for March). It takes place before the events of the game, which is why you see Strawberry and Canola as knight school students instead of apprentice knights.

As an aside, Canola's limited voices also say that these two give each other Valentine's Day/White Day gifts.