Investigations were a great reference feature added in Suikoden II also in Suikoden III, which allowed a player to learn more about the characters that inhabit his/her headquarters. Investigators could also hint the hero, on how to recruit other stars of destiny.
Investigations are typically carried out by the Chiyu Obscure Star or are related to the Teni Star (Strange Star).
In Suikoden IV there was no investigator, so they added a Confessional, where the player could hear the confessions of their different characters. Like the investigators, Deborah took the role as a psychic would could tell the player who and where to recruit the next character.
In order to do the investigation, Detective is required.
Suikoden II[]
Each investigation per character has an increasing price, usually starting at 100-200 potch, getting as expensive as 800 potch for the final investigation.
After choosing a particular character to investigate, Richmond disappears for approximately 5 minutes. After five minutes, if you leave the room and re-enter, Richmond will be back with the results.
There are 2-4 investigations per character. For 110 characters, at 5 minutes, and 3 investigations, this adds up to about 27 and a half hours of play time spent. So, Instead of spending all that time doing it yourself, you can just look them up right here.
Suikoden III[]
Each investigation per character has an increasing price, starting at 100 potch, getting as expensive as 400 potch for the final investigation.
After choosing a particular character to investigate, Kidd will disappear for approximately 5 to 10 minutes. After this amount of time, if you leave the area and re-enter, he will be back with the results.
Suikoden IV[]
Investigations in Suikoden IV were performed by the hero himself, once he acquired a confessional. The confessional was built at the headquarters once the character Keen was acquired. Deborah took the lead as the go to person, on how to get new recruits.
Suikoden V[]
Each investigation per character has an increasing price, starting at 100 potch, getting as expensive as 300 potch for the final investigation.
After choosing a particular character to investigate, Oboro will disappear for approximately 10 minutes. After this amount of time, if you leave the room and re-enter, he will be back with the results.
Suikoden V introduces a new feature, the Whereabouts, where the player can investigate a character that is not recruited yet, to have some infos where he could find him.