This tag is for a group consisting of only males engaged in sexual activity. No females. No dickgirls. For a group of mixed sex, tag 'mixed:group' should be used regardless of gender proportions.
Courtesy of Google translate: Pg. 24 has Nitori panicking about the cum reaching her hair, and one of the men laughing at her for being a bad Kappa that can't breathe in jizz. 32 and 33 is the last man remarking that he'll dump her in the mountains after one final go with his nose plugged