"In my Shadow" - Miya Atsumu Angst (with happy end)

The first time he noticed something odd was while grocery shopping with Kita, the next when on a date with Sakusa. He blamed it on pre-game nerves since they had an important match that weekend. However, the last time he noticed something odd was at the after-game celebration... and this time it didn't stay an odd feeling in his shadow.

Or, Miya Atsumu has without noticing it acquired a stalker. A fan that was a little too obsessed with the famous setter and goes to disturbing lengths to show it.