Even so, regardless of the many suspicions, due to a lack of evidences and witnesses, there was simply no way to prosecute Eva Ushiromiya, nor to conclude that a crime was committed at all. Int the end, the case was archived.
Up to this point it was still called the "Rokkenjima explosion incident", or simply the "Rokkenjima incident". It occupied the first pages of many newspapers for about a month, but the public interest waned pretty soon. Even considering the extremely unusual situation and the many unanswered questions, it still lacked that something that would make it the center of speculations and conspiracy theories for years to come. Of course that something later materialized itself in the form of two peculiar findings, but before that, it is probably useful to remind who were the members of the Ushiromiya family.
Let's start with Kinzo Ushiromiya, the family head. If you could sum up all that was written about him, you would get several books thousand pages long, and as it is often the case with extraordinary men, discerning facts from legends is very difficult. It seems that most of his relatives died in the great Kanto earthquake of 1923 when he was still very young. He himself and his parents were unaffected by it because at the time they lived in Taiwan. The Ushiromiya used to be a wealthy and powerful family even back then, but the earthquake destroyed most of their holdings, so, while it is only thanks to that tragedy that Kinzo was appointed as the new head, it is also what left him with nothing but ruins to inherit. Not much else is known about the following years. It seems that Kinzo kept a low profile and he never made use of his talents. However it is believed that an important event happened during the second world war. Kinzo actively participated in it as a soldier, but he was never sent to the front lines, so it is hard to speculate what could have changed him that much. The military are notoriously tight-lipped, and with the confusion that followed after the unconditional surrender and the american occupation, it isn't strange that not much is known about what Kinzo was involved with. What is certain is that he returned from the war as a different man. From that point onward he started making several crazy investments as if he was possessed by a demon. His economic strategies were hazardous to say the least, no matter the risks involved, he would bet everything he had even if failure would have meant dragging his whole family into poverty. Miraculously Kinzo always won his bets, and as a result he gained a ridiculous amount of wealth in a very short time.
Those were years of radical changes for Japan. For the many noble families and the bourgeois of those times adapting to the new situation was very difficult, but Kinzo was different. Having spent his childhood far from the mainland, his mind was more open to the world, and he was fluent in both Chinese and English. Notoriously Kinzo has always been fascinated by the western culture, to a maniacal level. All of that helped him immensely in establishing good relations with the GHQ, and that gave him several advantages over any other competitors.
Kinzo was married with a woman that he, reportedly, never truly loved. He was forced to marry her when he was still young, soon after he was appointed as the new family head. Even so he had four children from her. Kinzo's wife was already dead at the time of incident, so there is no point in remembering her. Her offspring and respective families, however, are quite important.
The firstborn son was Krauss Ushiromiya. All of Kinzo's children and grandchildren were given those strange western sounding names. His fanaticism for the west was that bad. As the one who was supposed to eventually become the new family head, Krauss spent his life in the attempt to replicate the outstanding achievements of his father. He failed miserably. To be completely blunt, he was an idiot who could be easily beguiled by unrealistic promises of huge profits. In 1986 Kinzo had already retired from the public scene, and he had left to his eldest son the duty to administer his empire. That wasn't really a wise choice, but it seems that in his latest years of his life he no longer cared about money, or the fate of his family. Krauss abused of his position and embezzled more than his due in order to make several horrible financial investments. After every failure, he would invest even more money in even riskier business to compensate for the losses. If he wasn't caught in that explosion, he would have probably ended up losing every single yen that his father gained, as unbelievable as it may seem.
Krauss was married with Natsuhi. Not much is known about her, as she rarely left the mansion, but the many servants that used to work for the Ushiromiya describe her as a very stern person. It seems that Natsuhi wasn't in good terms with Eva. As the wife of the next in line for the title of the family head, she desired for her role to be recognized. However Eva would not consider her anything more than a borrowed womb meant to provide a heir for her elder brother. It seems that Natsuhi greatly suffered from the scarce power that she was granted in the rigid rank system of that family. Tragically she was a failure even as a borrowed womb. It took her twelve long years before she was finally able to bear a child, and that child turned out to be female.
Krauss' and Natsuhi's daughter was named Jessica, at the time of her death she was 18 years old. Just to confirm her mother's inability to provide a suitable heir for her husband, Jessica never learned to behave as her position required from her. She was an unrefined tomboy, absolutely unladylike, and she lacked in intelligence. Overall she was more suited to live a commoner's life.
Krauss's family members, along with Kinzo, were the only permanent residents of the Rokkenjima mansion, excluding servants. The remaining Ushiromiya all settled in Tokyo, and only traveled to that remote island for the annual family meeting or other special occasions.