Regarding Aria’s revealed skill “Tsukkomi EX” in chapter five of “The Hero Suddenly Proposed to me, But . . .” (Yuusha-sama ni Ikinari Kyuukonsareta no Desu ga), it was left untranslated in the scanlation of the manga but it was explained in the notes. You can read chapter 5 here (with the notes).
Tsukkomi EX Explanation
This is a cultural thing which means that it’s difficult for non-Japanese to understand.
“Boke and tsukkomi are loosely equivalent to the roles of “funny man” or “comic” (boke) and “straight man” (tsukkomi) in the comedy duos of western culture. Outside of owarai, boke is sometimes used in common speech as an insult, similar to “idiot” in English, or baka in Japanese.” Wikipedia
Basically, it’s a comedy skit/routine that is popular in Japan. The “boke” says/does something stupid while the “tsukkomi” inserts common sense into the mix.
Tsukkomi EX Analysis
A fan said that “A tsukkomi is a form of joke that shoots down idiocy when it sprouts so I’m assuming her skill is a high level idiot sniper.” 😀 I agree. Of course, for a Tsukkomi EX skill to develop there has to be an equal amount of boke moments. In short, Aria must be surrounded by silly or unreasonable stuff all the time.
The “EX” part apparently refers to a skill that is hidden, according to this very useful post (spoilers). It has all of the skills and stats of the main characters but please beware of spoilers!
Here are examples – Ultimate Tsukkomi (Katekyo Hitman Reborn)