下級生: underclassman

天球: celestial sphere

casual amateur baseball

sincerity, true heart

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

(literally) one side / everywhere, all around, the whole area / one viewpoint, one opinion or way of thinking / the front page of a newspaper

for the time being, for the present

the basics, a general idea

the famous of the “one hundred poems by one hundred poets” anthologies, compiled by Fujiwara no Teika in c. 1235, used in the basis of certain card games

Alternative form of ひとりぼっち (hitoribotchi)