Treasure To Be Found

Twins named Yumi and Yuna Tanaka lived a content and quiet life with their father, older brother Akashi Tanaka, and Akiari Tanaka along with their best friends Hikaru and Akira Sato and their long time helper Nana Yui in Tokyo after relocating from Nara when the Ito family threatened them and made a deal, resulting to arranged marriage by force. At the age of eighteen, Yumi runs away after finding out that she's set to an arranged marriage with Hitoshi Ito as he attempted to rape her during their family's meeting as they offer to invest in their family's military company and as Akashi saw the attempted rape, he stopped it and called for attention, leading to war with the Ito family and having to hide with the help from the Sato family to lead them in living at the military quarters after relocating and the death of Akari Tanaka. They live their lives in hiding as Yumi escaped with Yuna to the military academy their father and brother once trained in as Fumihiro and Akashi begin to worry all the more after the rebellion of Yumi. Upon arriving at the military academy, they are with Hikaru and Akira along with fighting against the Ito family and their operations around Japan. Together, they face hardships together. What is the treasure that they seek for the most?