[Sakamata Nerimono] It's All The Gal Nee-chan's Fault 4 (COMIC Shigekiteki SQUIRT!! Vol. 23)

A group of voluptuous older sisters with contrasting styles—from ponytailed gyaru to composed long-haired types—corner their younger brother in an escalating, steamy harem fantasy. What begins as a teasing beach trip with bikini-clad women in garter belts and stockings spirals into a relentless domination, with the busty women declaring he must take "responsibility" and vowing to dry him out daily. The tension between the boy's overwhelmed state and the sisters' assertive, toy-wielding advances drives every page of this decadent summer escapade.