Watch Out for the Detective in Hanamachi

[Light literature + reasoning + daily life? +Group portrait] "It's an obscure story." Someone after reading this came to this conclusion. On that ordinary winter day in 2012, Yiyang Iizumi lost the daily routine he had experienced in his campus life due to a sudden accident when he was eighteen years old; Two years later, at the beginning of 2015, his sister embarked on a journey to find her missing friend; Then in 2016, a series of murders occurred on the Snowpiercer heading to Hokkaido, a secret room murder in a school in the late autumn of 2007, a kidnapping in a mental hospital in the early summer of 2010, and in 1986, a secret love from someone in the Ural Mountains during the Soviet era... What is the truth that connects the above seemingly unrelated events? Where did everything begin? In the midsummer of 2019, a young man joined the detective agency located in Idama City's Rishika Town———— Then here comes the problem. Regarding the answer to all this, what is the true truth of the so-called Hanazinhana Town...? (Practice writing)