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Koichiro Saeki
Koichiro Saeki
Kanji {{{Kanji}}}
Age 15
Gender Male
Professional Status
Occupation Unknown
Personal Status
Status Alive
Anime 1997 Series Episode 13 Treasure Island Murder Case

Koichiro Saeki was Professor Saeki's son. He was disguised as Midori Mimasaka in the Treasure Island Murder Case.


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Professor Saeki: his father.

Midori Mimasaka: his late lover.


Koichiro Saeki was Professor Saeki’s son, and his mother was an American. Ten years ago, his father was doing research on legendary treasures, and he was the leader of a group having four other members- Mimasaka, Kakimoto, Yasojima and Yaogi. The group was searching for the treasure in an island, when Professor Saeki accidentally found it himself. He hid this discovery from his teammates, and brought only his son, Koichiro, to see the treasure- bars of gold, stacked in a huge pile. There, the professor told his son about the dark side of all that beautiful gold. People had lost their lives trying to get it. He intended to donate the treasure to the country, away from greedy hands. However, soon enough, the other four people found out about the discovery, and they opposed Professor Saeki’s decision. While they were all still on that island, the four tried to get Professor Saeki spill out the treasure’s location. They cornered him on a cliff, but he lost his footing and fell onto the rocks below. Saeki died, and his colleagues, not knowing what to do, abandoned their search and left the island. What they did not know was that Koichiro had witnessed all that had happened. As he looked at his father’s battered body, Koichiro swore to take revenge on the four men.

Years later, Koichiro was living in America. There he met Midori Mimasaka, the only daughter of one of his father’s murderers. He pretended to be her friend, waiting for a chance to take revenge. However, as time passed, he got to know her better and realized she was a sad and lonesome woman. Her father had abandoned her, and she had no relatives to rely on. Koichiro and Midori eventually fell in love, but sadly, Midori committed suicide. She had received a letter from her father, and he was asking her to take part in a treasure hunt with him. If they ever found the treasure, she would help him kill all the other participants. He also wrote about how they killed Koichiro’s father ten years ago. All of this was enough to make Midori choose death, and Koichiro lost the woman he loved. His disgust at her father’s greed reignited Koichiro’s desire to murder him and his other three comrades.

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