Progear is an arcade video game developed by CAVE and published by Capcom on the CPS-2 arcade system board in 2001. This was Cave's only horizontal scrolling shooter until Deathsmiles in 2007. The game features a steampunk-like style and art design. This game is the second of two CAVE shoot 'em ups to be released in America with the third CAVE NTSC-U/C release being Princess Debut, and in limited print; and as a result, the US version is somewhat rare. Sometime in the past, the people of the country of Parts had found a way to become immortal, but only with elderly nobles. Five of these elders—Ballossum Pench, Gabriel Hammer, Jimchuck Spanner, Olsorro Slasher, and Leonard Drill—obtained immortality, and became known as the Motoruin sages. Eventually, they attempted to take over the Parts kingdom and start a new world order, collapsing the government and destroying parts of the country in the process. As their plans unfold, five children of one of these villages decide to battle the Motoruin using another new invention: the semi-automatic propelling engine, known as "Progear". At the start of the game, the player is given a choice between two pilots/planes and three gunners, which determines the effectiveness of their respective modes. Each character's costume can be changed by holding the start button at the selection screen.

Sometime in the past, people of the kingdom of Parts found a way to become immortal but only with elderly nobles. Among these elders who obtained immortality were Ballossum Pench, Gabriel Hammer, Jimchuck Spanner, Olsorro Slasher and Leonard Drill. They later became known as the Motoruin sages, eventually attempting to take over the Parts kingdom and began a new world order, collapsing the government and destroying villages of the country in the process. As their plans unfold, five children decided to battle the Motoruin using another new invention: the titular semi-automatic propelling engine.