H2O: Footprints in the Sand is a Japanese adult visual novel by Makura that was released on June 23, 2006 for Windows as a DVD; a version playable on the PlayStation 2 under the title H2O + followed on April 24, 2008 with adult content removed and added scenarios and graphics not seen in the original release. H2O is Makura's first game; a sequel named Root After and Another was later produced in October 2007. The gameplay in H2O follows a plot line that offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the three female main characters. There are two modes of gameplay, the Blindness Effect and Normal Effect, where the former plays on the fact that the protagonist is blind, and the latter mode removes the added element of gameplay the Blindness Effect has. The story is broken into three parts: the original introduction and meeting, following by a separation and reunion, and finally ending with the protagonist choosing one of the girls and spending the rest of the game with her.

"Footprints," also known as "Footprints in the Sand," is a popular modern allegorical Christian poem. It describes a person who sees two pairs of footprints in the sand, one of which belonged to God and another to themselves. At some points the two pairs of footprints dwindle to one; it is explained that this is where God carried the protagonist.