Normal tea sweets are not that explicit, but this one is what it is: a strawberry in もち dough
I like to make a pun on the homophone 一期, quite useful for presentations where you can't bring a scroll.
For the smaller Extra strawberries you can get from Migros (about 10 gr each), I find 15 gr あん and 20 gr もち perfectly fine
I added a few drops of balsamic vinegar to the あん here (about 2% by weight). It hides well behind the あん flavour, but it makes the strawberry flavour pop a lot, so I think it's worth it!
The problem with fruit もち in general is water migration. So the あん also acts as a buffer to prevent the fruit moisture dissolving the もち layer. Hence the strawberry is wrapped in あん.
Sogginess
You can sprinkle the strawberries with sugar, which draws out moisture, and then pat them dry
You can use an agar film (1% agar, heat to dissolve, cool to 50°, dip fruit into it)
In European sweets, you'd abricotiner or use cake glaze or pectine
Ideas
I tried coring the strawberries and piping the あん in them. This works and tastes more balanced (because you use much less あん), but you have an issue with sogginess.
I tried dipping the cut end of the strawberry in white chocolate, but I was inpatient and didn't wait for it to harden before wrapping them. I think this approach might work, leaving them for 1 hour in the fridge after dipping.
However: The hard chocolate is a bit unexpected in the normally soft 大福. So you need to warn people. I think the approach with agar is more promising.
Also: The shape is a bit odd; the strawberries peek out if you wrap them from the tip. In one presentation I said it looked like the morning sun kissing the snow-covered mountain top, but it looked a bit amateurish.
One way might be to decide on a front side and start the wrapping from there?
Sometimes, the もち are cut and the strawberry inserted à la minute. This could make sense for presentations, but it looks very un-tea.
Pomegranade molasses instead of balsamic
Make もち dough with milk, yoghurt or coconut water.
Liquorice or anise seed in the dough (it's a nice pairing with the strawberry and balsamic あん)! I tried it with very few anise seeds, and that didn't do much. Next time, try 1 gr for a batch.