Snow

Why did the Chinese have a panzer I.. Japan was one of Germany's allies wasn't it. :/

I was just as confused, it was part of a modernisation effort of the Chinese Army, they bought 15 Panzer 1 Ausf.A in 1930. They arrived in China in 1937 with barely enough time to train the Chinese Crewmen to operate these tanks. They never saw service in the battle of Nanjing, but were ultimately lost along with the city to the Japanese. 

Another Picture of abandoned Panzer 1's due to being outnumbered and out performed by the Japanese.

Equipped with DP Machine Guns.

Captured Chinese Panzer 1 being paraded around Mainland Japan.

Also found this article on "That one time the Nazi's helped China fight Japan".

https://medium.com/war-is-boring/that-one-time-the-nazis-helped-china-fight-japan-42ce2fa6c6d