~ʚ()ɞ~ Miracle Time - "It started with a scribble". One day, Someya Mai writes something on her desk and, to her surprise, a reply suddenly appears! After a moment of confusion, considering whether it's a spiritual phenomenon or just the result of her being in shock, she asks who is writing...It turns out she can communicate with a boy, whose name is Mayumi Shinichi, living 6 years in the past through the notes written on her desk, which becomes like a time machine connecting the past and the future!
A story from the collection "Angel Time" (1 Volume - Complete) - It'd be interesting to read the other stories as well, as they all have some sort of time theme...
Cute manga