A male high school student finds a beat-up, antique portable gaming console (think Game Boy or PSP) in the school bathroom. When he turns it on, he doesn't see Mario or Pokemon. He sees Hanako-san. The ghost explains that she is trapped inside the game cartridge. The only way to "release" her is to... play specific mini-games. However, a rival spirit appears. Hanako must "battle" (vs) the male student using the "M Portable" (the cursed console) to determine who controls the bathroom.
There is a surprisingly large niche of adult content focused on "obsolete technology." Game Boys, CRT TVs, VHS tapes, and floppy disks. The "M Portable" is a fictional stand-in for the Sony PSP or Nintendo DS. The idea of a ghost trapped inside a game console that you have to physically interact with (press buttons, blow on cartridges) plays directly into the Japanese aesthetic of mono no aware (the bittersweetness of things) mixed with fetishism.
The production utilizes the grimy, claustrophobic atmosphere of Japanese school buildings to maximize the tension.
The "vs" in your search likely refers to the conflict between the and Hanako-san (Ghost) :