Rami Nana-Hikari's adventures continue as the keeper of the Secret Treasure. A year has passed since the apocalyptic disaster which left a great crater in the center of Edo City. The destruction wrought major economic consequences and while much investment was poured into the public works for the new Edo Castle, the citizens were all feeling the pinch of the recession.

Fifteen-year-old Umika Konohoshi is having a hard time socializing at school, but she hopes her words will someday reach other people. When self-proclaimed alien Yuu Akeuchi enters her life, Umika will learn more about being open.

After graduating from a top university with an impressive extracurricular record in the rugby club, Akira Tendou has nailed every step of the way to securing his dream job. On top of that, a beautiful and kind co-worker always brightens his day in the office! Life seems to be going very well for Akira until he slowly realizes that sleepless nights and brutal work are his new reality. Due to three years of mind-numbing labor in an exploitative company, Akira is unable to recognize the tired, unaccomplished person he has become. On track to losing all passion in life like several of his overworked colleagues, Akira finds his saving grace in the most unexpected way possible—the breakout of a zombie apocalypse. With the free time he finally has, Akira decides to complete a bucket list of a hundred things he wants to do before he eventually gets turned into a zombie. Although he is surrounded by the dead, Akira has never felt more alive!

Ron Kamonohashi, the best student in the history of the elite Detective Training Academy BLUE, has been living as a recluse since BLUE expelled him five years ago. Moreover, he is forbidden to work as a detective, having barely escaped execution after getting involved in a murder case while he was still attending the school. Ron's situation changes drastically when police detective Totomaru Isshiki, following the advice of a senior colleague, seeks him out for help with a criminal case that has remained unsolved for months. Ron reluctantly agrees to help Totomaru and uses his phenomenal intuition to discover the culprit in less than a day. However, it appears that Ron suffers from a mysterious condition that can cause those around him to lose their lives. To Ron's great surprise, Totomaru manages to save the life of someone whom Ron put in jeopardy. As the unlikely duo starts solving crimes one after another, BLUE sends operatives after its former student to find out if he has resumed investigative work. Fighting against murderers, rogue detectives, and the Metropolitan Police Department, Ron and Totomaru must join forces if they want to survive and see justice prevail.