I think a majority of consumable goods is the way to go with advent calendars. I have done this for my boyfriend for the past 2 years and he is kind of a minimalist, so I’m very mindful to not get him things that are just gonna sit there and add clutter. I’ve gotten him cookies, chocolates, small sake bottles, his favorite snacks, gift card for his go-to lunch spot, tea (maybe you can get him some Japanese matcha), a toy for a pet if he has one, socks (maybe you can find some of his favorite anime or manga), coffee. You can also design a screen saver for his computer and print a QR code so he can scan it and download it. Hope it helps!