It's hard to say exactly who the hero in the very first hero's journey story was as hero's journey stories date back to ancient times and different cultures have their own early examples. However, Gilgamesh from 'The Epic of Gilgamesh' is often considered one of the earliest heroes in this type of story. He was a king who had to face many challenges on his journey to find immortality.
The music for the first episode of Vigor Hero was composed by the Japanese composer, Takeuchi Usuri. Takeuchi Ushiho was a famous agricultural anime composer who had created many Japanese anime works, including Sword Art Online, Fate/Stay Night, and Your Name. Wait.
The first episode of "Vigor Hero" had a variety of music styles, ranging from light pop songs to intense battle music and warm emotional music. The music played different roles in different scenes and plots, bringing a rich musical experience to the audience.
The first hero to appear in Water Margins was Shi Jin. He was the son of Shi Taigong of the Shi Family Village. He was ranked 23rd among the heroes of Liangshan and seventh among the Eight Tiger Cavalry and Vanguard of the Horse Army. Shi Jin was the disciple of Wang Jin, the instructor of the 800,000-strong Imperial Army in Tokyo. Because of the nine green dragons tattooed on his body, he was known as the " Nine-Striped Dragon." His appearance set the tone for the whole story, showing his chivalrous courage and heroic spirit.
To be honest, I don't have a definite answer for you. The determination of the first masked hero novel is complex and could involve many considerations that are not straightforward to define.
One could argue that Hercules from Greek mythology was one of the first fictional heroes. His legendary strength and adventures have been passed down for centuries.