On the Nintendo Switch side, start Tatsumori as a user using the linked Nintendo account, and press the "-" button on the title screen to open "various settings". Here, press "Tanu Portal Settings" and you are ready. To use Tanu Portal at Atsumori, you must subscribe to the paid service "Nintendo Switch Online".
Preparation is now complete. The following functions are mainly available in "Tanu Portal".
■ Chat input
You can chat the game by smartphone input. This is only possible when online. If you use this function, you can use kanji that cannot be input in normal play. Voice chat is also possible in addition to chat input.
■ Read my design of past work
You can read past designs using your smartphone camera. The corresponding titles are Nintendo 3DS "Tobidase Animal Crossing" and "Animal Crossing Happy Home Designer".
▲ Screenshot of smartphone side. It looks exactly like the smartphone UI used by players in Atsumori.
The smartphone app "Nintendo Switch Online" can be used for online communication not only at Atsumori but also at "Super Smash Bros. Smash Bros. SPECIAL" and "Splatoon 2".