From Russell

"" is an Series: in. As its name suggests, it is a ST: from the Guard Captain ST:.

Location and Uses
ST: can collect the ST: "ST:" at any ST: after he completes the ST:. In it, the Guard Captain ST: invites ST: to try the new ST: program he has just begun holding at ST:. The ST: reads,

"Hello, Recruit! How's the sword training going? You should consider testing your skill against more experienced swordsmen. If you want to take your technique to the next level, stop by the training room in the castle. We're waiting for you! -- Guard Captain Russell"