i know i was dumb and uploaded the original without even knowing that people uploaded the song already XD but i am sure no one uploaded the piko and len version. i found this on youtube and i liked it and i was so happy to see a download link so you guested, i wanted to share with you guys :D 

Piko & Len - Promise

hello~! i'm Yuki chan~! i am a person who enjoys sweets,sushi,hetalia,kawaii things,anime,minecraft,nekomimis,drawing,playstation,and of course music (especially vocaloid and japanese music) i am a very cheerful person and could get inspired easily. anyway it was nice meeting you and keep posting those wonderful songs ^^

Piko & Len - Promise

Yukicupcakez3