Looks like the princess was very smart -what she needed was wisdom, how to use what she could do. Rou gave her a little of that. Painfully. 
The Galactic Navy Officer Becomes an Adventurer
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM