One day after the proclamation, Soeprapto, friend of Hoegeng's father, gathered the police members, including Hoegeng and his superior Soekarno Djojonegoro, and told them about the independence of Indonesia and that there was to be a transfer of power. In October, Hoegeng was admitted to a hospital (now Karyadi Hospital) in Semarang after suffering concussion during his duty guarding Japanese prisoners. At that time, the Five Days Battle between Indonesian fighters and Japanese prisoners occurred. In the morning before the hospital was stormed by the Japanese, Hoegeng fled because he didn't like the hospital atmosphere and fled from the place he was treated. After the battle began to cease, Hoegeng was recommended by doctor to rest. He then took leave and rested in Pekalongan.