New info:
When I ascended to level 6 on WaniKani, which is roughly the 240th Kanji, I got the email notification with the following hidden message. EDIT: Fairly certain we’re on the right track, since level 26th email refers to the Durtle in B2, thanks @pahko and @dasding!
Message Screenshot
The image within the mail has what looks like to be a message on the tomato as well but the resolution isn’t good enough to make out the details.
Tomato Text
EDIT: Looks like each level up e-mail may contain a piece of the clue! Everyone, please help by checking your email and you can help by contributing here:
https://docs.google.com/spreadsheets/d/1b594hcK9QqmNumnWpbAAeUEQ8QBMSOl6Yu7jdOw-PXU/edit?usp=sharing
To check the hidden message in gmail
Step 1: Click on the hamburger menu then click "Show Original"
