to inject / to pour into / to concentrate / to pay attention / stake (gambling) / classifier for sums of money / variant of 註|注[zhu4]
注
=
主
+
氵
:
Julian Giant Squid and the lord are very concentrated on a game they are playing in the space station's bathroom. Each of them has a bottle of water, and they are taking turns to pour the water in the other one's bottle, which is not that easy at zero gravity.