Hi, which day and what time period were you trapped at?
About the skill, if you are talking about convenient store, there is only 1 level for that job.
Viewing post in Bottle Biosphere -Living with a runaway girl- comments
This is probably a rare case which you didn’t increase Fuyuka’s romance point enough to trigger the next event for too long, as results trapped in the very early stage of the game.
Try headpat her everyday, bath before sleep, pick the right answer in conversation. Then it should be able to trigger the next event and unlock the option to buy her gift.