王仁: Wani, a possibly legendary immigrant to Japan from the Korean peninsula kingdom of Baekje, invited during the reign of Emperor Ōjin (270-310 AD); notable for purportedly bringing the Analects of Confucius and the Thousand Character Classic to Japan (though this is controversial; see the Wikipedia article on Wani for details)

small piece, particle, fragment / (chiefly in the negative) small amount

苦しむ: to suffer

winter (season)