To hand a gift to someone causes themn to incur a feeling of responsibility to return the favor. That is not the goal. So to achieve the goal of expressing thanks while simultaneously avoiding their incurring any debt, the culturally appropriate thing to do if giving a gift is to give a gift that person can share easily with their whole team. The fact is all people here work in teams. A building manager does not see the building being satisfactory to you as his doing alone. Rather he would see it as the successful integration of the efforts of all staff associated with the bulding functioning properly. The same is true of gym attendants, parking attendants, receptionists, etc.

Suggestions include senbei (rice crackers), cookies, chocolates, or other similarly individually wrapped or delineated within a larger box items from wherever you have returned recently. Home town specialties are very good too because it shows a bit of sharing of yourself with the team. Which in turn is in and of itself team building.

To give any gift at all is not necessarily customary, nor even expected, but if done within the parameters of the culture, very well received.

Mike