The following steps may help with the issue.
-Confirming the available storage space on your device.
*6GB or more of additional free space is recommended when using this app.
-Close all other applications running concurrently with My Hero Academia: The Strongest Hero.
-Restart the apps and your device.
-Clear your cache/app data
-If you are still seeing common technical issues it could be because of corrupted data. In this case, it may take some time but please try the following:
1) Make sure your account is linked (or that you have created a link password)
2) On the title screen select Repair -> Confirm
This will have you redownload much of the data again and may fix any errors.