sayonara zetsubou sensei, osomatsu-kun, osomatsu-san, faceless male, matsuno karamatsu, karamatsu, matsuno ichimatsu, ichimatsu, matsuno juushimatsu, juushimatsu, matsuno osomatsu, osomatsu, matsuno choromatsu, matsuno todomatsu, choromatsu, todomatsu, itoshiki nozomu, kamiya hiroshi, itoshiki nozomu (cosplay), black border, :>, 6+boys, bdsm, bondage, border, brothers, character name, derivative work, faceless, hands, layered clothes, limited palette, male focus, multiple boys, noose, rising sun motif, seiyuu connection, sextuplets, shibari, shibari over clothes, siblings, smile, solo focus, sunburst, sweat, tears, wafuku