eating the first product of the season make one live longer / a wonder lasts but nine days

(Shinto) the gods of calamity or misfortune

radish, Raphanus sativus, (specifically) small red radishes

(literally) know the other side and yourself, a hundred battles will not be perilous

Kyūjitai form of 六角四片四角孔ねじれ正多面体: muoctahedron

(idiomatic) living a life without achieving anything great

24-cell; regular icositetrachoron

Kyūjitai form of 正二十四胞体: 24-cell; regular icositetrachoron

“a hundred days of sermonizing, one fart” → a metaphor for how something that one has put great effort into can come to nothing after even a slight mistake, much as a hundred days of serious spiritual study can be lost to the winds

(lit. one eye, two legs/feet, three courage, four power) "first, eyes, second, feet, third, courage, fourth, power". The essentials of [kendo] in descending order of importance