Vocabulary consisting only from characters you are able to read
直火
jikabi
open fire, direct heatmix
開放
kaihou
open, throw open, liberalization, liberalisationsuru
開店
kaiten
opening (of a shop)suru
開閉
kaihei
opening and shuttingsuru
開会
kaikai
opening of a meetingsuru
開通
kaitsuu
opening, open, taking effect, becoming activesuru
大作戦
daisakusen
operation, planmix
視点
shiten
opinion, point of view, visual pointmix
反対
hantai
opposition, resistance, antagonism, hostility, contrast, objection, dissension, reverse, opposite, vice versajlpt3, jlpt4, leda1, suru
反抗
hankou
opposition/resistance/insubordination/defiance/hostility/rebellion/(P)leda1, suru
最適
saiteki
optimum, the most suitablemix
順序
junjo
order, sequence, proceduremix
体制
taisei
order, system, structure, set-up, organization, organisationmix
常微分方程式
joubibunhouteishiki
ordinary differential equationmath
鉱石
kouseki
ore, mineral, crystalmix
器官
kikan
organ (of body), instrumentmix
構成
kousei
organization, organisation, configuration, compositionsuru
体系化
taikeika
organization, organisation, systematization, systematisationsuru
原点
genten
origin (coordinates), starting pointmix
由来
yurai
origin, source, history, derivation, reason, destinyall
原意
gen'i
original meaningmix
原状
genjou
original statemix
目新しい
meatarashii
original, novel, newadj
独自
dokuji
original, peculiar, characteristic, proprietarymix
元来
ganrai
originally, primarily, essentially, logically, naturallymix
元祖
ganso
originator, founder, pioneer, inventormix
孤児
koji
orphan; orphanmix
他
hoka
other (esp. places and things)/the restadj, leda1
外
hoka
other place, the restjlpt5
余人
yojin
others, other people; others, other peoplemix
場違い
bachigai
out-of-place, inappropriate, sticking out like a sore thumbmix
州外
shuugai
out-of-statemix
宿
yado
outcasts (those from Kamakura period to the Edo period, common around the Kyoto region); inn, lodgingmix
屋外
okugai
outdoors, alfrescomix
外出
gaishutsu; sotode
outing, trip, going out; (n,vs) outing, trip, going outsuru
域外
ikigai
outside the areamix
向こう
mukou
over there, opposite direction, across the wayjlpt3, jlpt5
優勝
yuushou
overall victory, championshipsuru
飲み過ぎ
nomisugi
overdrinking, excessive drinkingmix
重なり
kasanari
overlapping, piling, stackingmix
持ち主
mochinushi
owner, proprietormix
太平洋
taiheiyou
Pacific Oceanmix
田んぼ
tanbo
paddy field, farmmix
苦しみ
kurushimi
pain, anguish, distress, suffering, hardshipmix
一対
ittsui
pair (of screens or vases, etc.)mix
紙幣
shihei
paper money, notes, billsmix
月極駐車場
tsukigimechuushajou
parking lot rented on a monthly basismix
役割
yakuwari
part, assigning (allotment of) parts, role, dutiesmix
部位
bui
part, position (in a whole, i.e. body)mix
参加者
sankasha
participant, entrantmix
関与
kan'yo
participation, taking part in, participating in, being concerned insuru
別れ
wakare
parting/separation/farewell/(lateral) branch/fork/offshoot/division/section/(P)jlpt3