Our resident sleuth has started a journal documenting his investigation into her journey. Specifically, he has discovered that two keywords relating to her trip will unlock a jeweled chest within Crusaders of the Lost Idols.
You can follow along with Kaine's investigation as he tries to crack The Case of the Warrior in Japan by signing-up to the Idol Times newsletter. Each email will contain more clues from his notebook, of which the first pages his notes are available below.

If you can solve the mystery, you can enter the code into the in-game shop to earn a free jeweled chest. Please note the code is only valid on PC/Web, but you can link your account to mobile using these instructions.
Good luck, Crusaders!