Koshonin Season 2

The new season opens with a string of deadly incidents involving guns sent to various people by someone known as "Summer Claus." The weapons seem to be part of a batch of 27 stolen guns, and so far 14 of them have been given out. Now it's up to Usagi and the rest of the SIT to recover the remaining 13 before there are any more casualties...
(Source: Tokyograph)