In fact, it was written with a broken brain, so you can enjoy it. Tizi-chan traveled to the world of Fullmetal Alchemist and traveled with Edward and the others. However, Tiko-chan herself is constantly being attacked due to many physical problems. She can only see with one eye, and it might happen that she wears a black eyepatch so as not to scare people and is mistaken for a pirate.
Tizi-chan sleeps next to Al every night, and her relationship with the two brothers can be said to be growing day by day (big mistake!!). However, after slowly deepening her knowledge and becoming a national alchemist, Tizi-chan deeply understood the reality that her husband (Lockon) had been resurrected in her original world, and began to accept that the bun-faced commander just had the same voice as her husband (Lockon), and that Lockon could not appear in this world.
So, in order to allow Brother Edward to recover his body as soon as possible, and Al to regain his body, someone started a meaningless pursuit of the Philosopher's Stone. As for the final plot, please be patient and watch it?