Warning: The following article contains spoilers for The Devil Is a Part-timer!
Juggling two jobs, one as a demon-king overlord and the other as a fast-food worker, takes a certain level of maturity to achieve. Living under the assumed name of Sadao Maou — while otherwise known as Satan Jacob, King Satan, or The Devil — The Devil Is a Part-timer!‘s reverse isekai lead, fortunately, has this quality aplenty, having quite a few years tucked under his demonic belt. Also, as we see revealed in the anime’s introduction and flashback scenes, the dark-haired, red-eyed devil is rather accomplished, having masterminded various evil campaigns (even though they were ultimately thwarted by the hero and human-angel hybrid Emi Yusa, formerly called Emilia Justina back in their home world).
Spoilers ahead.
Before arriving in Tokyo, Japan from the fantasy island realm of Ente Isla (an otherworldly territory he had attempted to subjugate through conquest), Sadao already had plenty of life experience. However, the experience of living hand-to-mouth in a cramped apartment whilst also rocking the part-time lifestyle is a new leaf turned for The Devil Is a Part-timer!‘s demon lord, albeit one that he masters with good grace, by always summoning a welcoming smile and offering polite service to MgRonald’s customers. So, just how old is he, then?
Sadao Maou’s correct age
Although his body resembles that of a young man (and despite his claim to be only 21 years old), Sadao is actually much older than he appears. In fact, by the start of The Devil Is a Part-timer!, he’s over 300. He also boasts a fake birthday, June 23. Even his height of 5’6″ isn’t technically real, as he’s truly much larger when in his natural demon form, in which he expands to the size of a giant.