Not bad, not bad at all.
Unfortunately however, it seems like this one has fallen into one of the two fates for an incomplete manga-- it was either a promo for the LN, or it was just... axed. I don't know, I don't really care. Either way, the characters were fun and not overly tedious (especially since these are literal 12 year olds lol), there was enough intrigue and twists/turns to make it feel clever, and overall it was a fun way to kill the afternoon.
In short, 7.5/10. Not era-defining or the greatest thing in the world, but not unreadable-- and trust me, I've read some unreadable shit in my lifetime. XDXD