Wallpaper A Day
Day 157: Yuru Yuri
1080p version
Credit to Yuki Tatsuya
Day 138: K-ON!/Yuru Yuri
SauceNao/IQDB/TinEye have failed me, so no source atm.
Day 112: Yuru Yuri
Credit to 結城辰也
Day 100: Yuru Yuri
Day 90: Yuru Yuri
Credit to たた＠3日目（火）西る01b for the original artwork
Wallpaper A Day 