That woman is "Yotaka." Once famous in the underworld as the strongest assassin, she is now a 33-year-old (and very unlucky) drug addict and alcoholic. She's enjoying her unemployed life in a rundown apartment. ♪ With her mind and body completely slack, Yotaka receives an invitation from her assassin friend, "Kohai," to return to active duty...!!

Will she return to the battlefield once again?! Yotaka!!!

(Source: Kodansha, translated)