To finish engagement ON/OFF operation in a short time and to prevent destruction of a transmission caused by clutch disengagement when excessive torque is applied.

This transmission 10 includes: a pair of first gear elements 16 and a pair of second gear elements 17 as at least two pairs of gear elements, respectively arranged between an input shaft 12 and an output shaft 14 rotatably supported; a first clutch 40 and a second clutch 42 as at least two pairs of clutches, respectively releasably coupling at least the two pairs of gear elements between the input shaft and the output shaft; at least a pair of noncircular gear elements 18 arranged between the input shaft and the output shaft; and a clutch 44 for at least the pair of noncircular gear elements, releasably coupling at least the pair of noncircular gear elements between the input shaft and the output shaft. The clutch for the pair of noncircular gear elements is composed of a dog clutch configured to be engaged only on an inclined surface.

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