Masaru waits for about 30 seconds, simply watching Koutarou. Mostly his feet.

Then, in a whooshing blur of motion, he's suddenly right next to the Vice-Captain, his sword making a shining arc through the air as he makes a fast slash at the other man's left shoulder. Little strength was behind it, and it could likely be easily deflected if Koutarou tried.

The fact that Masaru almost immediately quick-stepped away from his opponent in a not-quite-Shunpo confirmed it had been a probing attack. There the Pack member waited, his stance light, almost...bouncy.