File 4: Ichibyou No Nedan
(rough translation: The Cost of the Best Painting)

An overweight jogger went out to run in middle of the night -- he told his wife that he was running to lose weight, but in actuality, he went to a "special" spot in a park to spy on a foreign couple making love. On his way home this particular night, the jogger was followed and stopped by a stranger. The strange asked him why he dirtied something that was suppose to be "beautiful" and proceeded to stab him to death.
The young couple were arrested since they were on scene when the police arrived. For some reason, the couple weren't talking. The cops assumed that the couple were illegal aliens and were afraid of being deported, since they had no ID on them nor did they respond to various languages spoken to them. Kyouya thought they were exchange students by their age, and that they may not understand Japanese well.
Kyouya questioned the arresting officer on why the couple were arrested. The detective cited that blood was on the man's clothing and the woman looked so scared that she must be guilty. Kyouya thought the pieces of the puzzle don't make sense; why murder a stranger in middle of the night and for no gain? The dead man wasn't robbed, after all -- it's obvious to most people that joggers don't carry lots of money when they go running. An argument ensued and eventually Kyouya left, saying that he'd prove the detective wrong. The detective in turn swore to prove Kyouya wrong and to find the murder weapon to do so.
Days passed. The accused man was still in prison, and still not saying a thing. The woman had lapsed into a catatonic state and was committed to a mental ward after the pair were separated. Kyouya went cavassing at the park and talked to a homeless man who was quite pissed off at the cops who arrested the couple. Kyouya learned from him that the couple "lived" down in the woods, also homeless, though he wasn't sure how long they'd been there. The homeless man was fond of the couple, saying that they brought "life and meaning" to the place. He liked them although they never spoke, and insisted that they couldn't have killed the jogger -- who apparently came to the park every night to spy on them making love.
Kyouya then went to the woods where the pair lived -- and noticed that in the midst of a perfectly condensed treeline, there was a hole cut away that gave someone at a bay window a perfect view. Kyouya sent someone up to examine the hole and discovered that the branches were cut away deliberately to provide the scenic view.
Meanwhile, the woman was dying.
Kyouya visited the resident whose window looked through the trees and discovered that he's an artist. Kyouya casually asked the artist what he knew about the murder but the conversation went instantly to his paintings. Kyouya remarked that they were nice and declined the gift when the artist told him to take it, citing that "they weren't my masterpieces." When Kyouya asked what his goal was, then, if he was already advanced so far.. the artist replied "beauty".
Kyouya's rival detective, in desperation for leads, united the lovers since the woman was dying. The boyfriend went mad when he realized that the detective was being humane only to expedite his work, not caring about her at all, when he let them be reunited, and in a rage attacked the detective. The pair left him unconcious on the floor and fled. Kyouya and Yamaki went to the park, assuming that was where they'd go to first. When they got there, they found the crying and frightened couple huddling in front of the artist with his unfinished "masterpiece", that he had been composing from his home watching them. He held the knife to them and demanded for them to look as before - beautifully in love. The artist confessed, like all bad guys do at the end of the story, that he killed the jogger to preserve the couple's beautiful love.
The woman, frightened and not understanding the demands, offered money. The artist felt betrayed; he felt that the couple had been corrupted and were no longer beautiful. He raised his knife, intent on murder, when Kyouya shot him in the hand. The final scene is the money with the portrait of love and blood.. symbolic.