Mediocre Samurai describes real life in historical Japan

Related links:
https://en.wikipedia.org/wiki/Katsu_Kokichi

And interestingly, despite Katsu Kokichi's low status and roguish history, his son went on to become a rather famous naval captain, government minister, and influential figure in Meiji Restoration period Japan:
https://en.wikipedia.org/wiki/Katsu_Kaishū

Military service

In 1860, Katsu served as captain of the warship Kanrin-maru (with assistance from US naval officer Lt. John M. Brooke), to escort the first Japanese delegation to San Francisco, California, en route to Washington, DC, for the formal ratification of the Harris Treaty. The Kanrin Maru, built by the Dutch, was the first Japanese vessel to sail to the Western world. Kaishū remained in San Francisco for nearly two months, observing American society, culture and technology. Following his return to Japan, Katsu held a series of high-ranking posts in the Tokugawa navy, arguing before government councils in favor of a unified Japanese naval force led by professionally trained officers in disregard of promotion and assignment due to hereditary status. During his command as director of the Kobe Naval School, the institute would become a major source of activity for progressive thinking and reformists between 1863 and 1864.

In 1862, the then rōnin Sakamoto Ryōma decided to assassinate Katsu due to his support of both modernization and westernization. However, Katsu persuaded Ryōma of the necessity of a long-term plan to increase Japan's military strength in the face of Western influence that led to the Convention of Kanagawa. Instead of killing Katsu, Ryōma started working as his assistant and protégé.

In 1866, Katsu was appointed negotiator between the bakufu forces and the anti-shogunal domain of Chōshū, and later served as chief negotiator for the Tokugawa bakufu, ensuring a relatively peaceful and orderly transition of power in the Meiji Restoration.

Although sympathetic to the anti-Tokugawa cause, Katsu remained loyal to the Tokugawa bakufu during the Boshin War. After the collapse of the Tokugawa forces in late 1867, Katsu negotiated the surrender of Edo castle to Saigō Takamori on 11 April 1868.

Later years

Katsu relocated to Shizuoka after the new Imperial government took control of the shogun's former capital, which was renamed Tokyo ("Eastern Capital"). He returned briefly to government service as Vice Minister of the Imperial Japanese Navy in 1872, followed by first Minister of the Navy from 1873 until 1878. As Katsu Yasuyoshi, he was the most prominent of the former Tokugawa retainers who found employment within the new Meiji government, and was sangi (参議) between 1869 and 1885 who did not come from one of the four paramount domains. Although his influence within the navy was minimal, as the Navy was largely dominated by a core of Satsuma officers, Katsu served in a senior advisory capacity on national policy. During the next two decades, Katsu served on the Privy Council and wrote extensively on naval issues.

He also made efforts to restore the honor of Tokugawa Yoshinobu and Saigō Takamori.

In 1887, he was elevated to the title of hakushaku (count) in the kazoku peerage system. Katsu recorded his memoirs in the book Hikawa Seiwa.