Willem Kmetsch (ヴィレム・クメシュ)
Background
He is the last human known to be alive 527 years after humanity went extinct. He was stone-frozen a year before it, under the age of 16. His resting-curses were lifted two years before the events take place.
He likes to play with kids (after growing up at an orphanage), although some mistake it for "him being into little girls."