校园里，真由子（堀北真希饰）、纱枝（戸田恵梨香饰）、志乃（仲村琉璃亜饰）、蓝（德永えり饰）是四个形影不离的高中女生，这几位好朋友拥有不同的性格：真由子文静内向；志乃古灵精怪；纱枝活泼开朗；蓝则书卷气十足。 “如果地球毁灭，你在那之前想干什么？”志乃的问题在女孩子们的心中激起了涟漪，原来她们都各怀心事：志乃爱上了帅气的结城学长，整日忧喜不定；纱枝拒绝了表白者，她的心中藏了另一个人；只是谁都没注意到真由子欲言又止的表情……蓝和不知名的人写着交换日记，对方是谁却成为了谜。 无忧无虑的生活不复平静，少女们的心情起起落落，就像泡泡般变幻多端，而又缤纷多彩。

Saya Toma is a female detective with an IQ of 201. Takeru Sebumi is a career detective with a distinguished background. They work on cases by postulating the "SPEC" of the unknown criminals and then deduce the criminal's unknown "SPEC" to make arrests. A mystery occurs when bodies are found on a cruiser in the ocean. Saya Toma and Ryo Kase of the Tokyo Metropolitan Police Department are brought in to solve the case.