A self-proclaimed angel installed a timer on a boy's arm, which will count down every time the boy's heart beats from interacting with his crush starting from 10. At 0, the boy will confess everything he is thinking at that moment.
Ok... this manga is not by Kawashita-sensei... BUT! The style look very similar! A few sample:
As for the story, so far till chapter 8 is not bad... so, do check it out!
You can get the English scanlation here: http://simple-scans.com/index.php?board=43.0