The Japanese military had been experimenting with semiauto service rifles for some time prior to World War II (most countries were, to some extent). There was some development of a Japanese Pedersen rifle, among others. The advent of the war cut most serious development efforts, as manufacturing capacity was needed to build the weapons that were already well-proven and in general use.
However, there was an attempt to copy the US M1 Garand rifle, which resulted in the Japanese Type 4 (often called the Type 5) rifle. It was a pretty thorough copy of the M1, but with a few distinctly Japanese touches, including the Arisaka-style sling swivels, front sight, and rear leaf sight (instead of the aperture used on the Garand). Instead of en-bloc clips, the Japanese opted for a 10-round internal magazine (in 7.7×58 semi-rim caliber), fed by standard 5-round stripper clips. Parts for about 200 of these rifles were made by mid 1945, though only a fraction of those were actually assembled into working guns.
These guns do show up for sale in the US from time to time, and bring pretty high prices. For folks who want to see one without the $20k purchase price, there is an example on display at the NRA National Firearms Museum in Virginia and another at the Cody Firearms Museum in Wyoming.