Ice-XII said: so, is this a continuation of the series or a side-story?
I think this is just a one shot comic Minami did. I couldn't this very well: 1月29日発売の星空のメモリアEternal Heartのゲーム中のSD絵とかそれなりに描きました。星メモファンの方はぜひ手にとって下さると嬉しいです…という意味がある程度込められた謎の星メモとちびミクさんのコラボ四コマ(゜□、゜)
but I think this is just in celebration of something coming out. so unless the next chibi miku is 442, making this 441, I don't think it's part of the Chibi Miku story.