Kimagure Orange Road OVA is basically the extension from the TV series. The time frame is probably in the middle of the TV series. 
Order to view with the TV series. 
White Lovers - among the episodes 35 and 45 
Hawai Suspence - among the episodes 17 and 25 
I was a cat, I was a fish - among the episodes 17 and 30 
Hurricane Akane, the shape-shifting girl - among the episodes 20 and 25 
Spring is for Idols - among the episodes 23 and 30 
Birth of a Star - Right after "Spring is for Idols" 
Unexpected Situation - after the OAV of Akane 
Message in Rouge - after the episode 48