Emoji and kaomoji have an important role in computer-mediated communication, as they can convey various paralinguistic cues and express the emotions of the writer. To examine how the Japanese use emoji and kaomoji, this case study investigates the pragmatic functions of emoji and kaomoji in Japanese YouTube comments through speech act theory and pragmatics. The data source for this study are the comments of one Japanese video published in 2022, a video titled [saikyō kankyō] Pokkī no desuku mawari shōkai!!! ([The most powerful environment] Introducing Pocky’s desk area!!!) uploaded by a popular Japanese YouTuber ポッキー Pokkī. Based on Searle’s speech act classification and the data, a taxonomy was created and used to categorize the comments with emoji and kaomoji, and then through pragmatic analysis, the pragmatic functions of emoji and kaomoji were examined. Similar to western character-based emoticons, it was found that emoji and kaomoji function as illocutionary force indicators. In the comments, emoji and kaomoji reflect Japanese nonverbal communication strategies, signifying formality and modesty.