Itinerary validity for jr pass 7 days

Hello, I'm just wondering if let's say I purchase the Jrpass 7 days. Can it be used unlimitedly to the locations in visiting. Such as going to and fro with shinkansen to himeji, Hiroshima and Kamakura.

I'm asking because I heard shinkansen can only be used one way instead of to and fro. I'm planning to use the pass most likely from day 3 onwards.

Day 1 (26/1)– Arrival in Osaka.
Day 2 (27/1)-Universal Japan
Day 3 (28/1)- Nara and Osaka city Day 4 (29/1)- Head to Kyoto, Explore city
Day 5 (30/1)- Himeji
Day 6 (31/1)- Hiroshima
Day 7 (1/2)- Shiragawa
Day 8 (2/2)- Leave shiragawa. Head to Tokyo
Day 9 (3/2)- Tokyo/ Kamakura
Day 10 (4/2)- Tokyo
Day 11 (5/2)- Tokyo
Day 12 (6/2)- Tokyo