List: word usually written using kana alone

usually written using kana alone  noun  noun (generic)  noun or participle taking the aux. verb する  intransitive verb 

• pinky swear (i.e. linking little fingers to confirm a promise), pinky promise

usually written using kana alone  noun  noun (generic) 

• Laportea bulbifera (species of nettle-like plant)

usually written using kana alone  noun  noun (generic) 

• oedogonium (any of a genus of filamentous green algae)

rarely used kanji form  usually written using kana alone  noun  noun (generic) 

• chytrid (any simple, algaelike fungi of order Chytridiales)

search-only kana form  search-only kanji form  usually written using kana alone  expression  い adjective  adjective (generic) 

• good (place to leave off), convenient

usually written using kana alone  expression  い adjective  adjective (generic) 

• popular

usually written using kana alone  expression  い adjective  adjective (generic) 

• easy to get into (e.g. of music, etc.), easily getting into (a certain mood, etc.)

usually written using kana alone  noun  noun (generic) 

• great-grandfather

slang  abbreviation  usually written using kana alone  noun taking the genitive case particle の  adjective (generic)  noun  noun (generic) 

• off-topic (on an online thread)

usually written using kana alone  な adjective  adjective (generic)  noun taking the genitive case particle の  noun  noun (generic) 

• smooth, flat, lacking bumps and dents
• featureless, uneventful
• noppera-bō, mythical being with flat featureless face