Background: Hikikomori is a severe form of social withdrawal, originally described in Japan but recently reported in other
countries. Debate exists as to what extent hikikomori is viewed as a problem outside of the Japanese context.
Objective: We aimed to explore perceptions about hikikomori outside Japan by analyzing Western language content from the
popular social media platform, Twitter.
Methods: We conducted a mixed methods analysis of all publicly available tweets using the hashtag #hikikomori between
February 1 and August 16, 2018, in 5 Western languages (Catalan, English, French, Italian, and Spanish). Tweets were first
classified as to whether they described hikikomori as a problem or a nonproblematic phenomenon. Tweets regarding hikikomori
as a problem were then subclassified in terms of the type of problem (medical, social, or anecdotal) they referred to, and we
marked if they referenced scientific publications or the presence of hikikomori in countries other than Japan. We also examined
measures of interest in content related to hikikomori, including retweets, likes, and associated hashtags.
Results: A total of 1042 tweets used #hikikomori, and 656 (62.3%) were included in the content analysis. Most of the included
tweets were written in English (44.20%) and Italian (34.16%), and a majority (56.70%) discussed hikikomori as a problem. Tweets
referencing scientific publications (3.96%) and hikikomori as present in countries other than Japan (13.57%) were less common.
Tweets mentioning hikikomori outside Japan were statistically more likely to be retweeted (P=.01) and liked (P=.01) than those
not mentioning it, whereas tweets with explicit scientific references were statistically more retweeted (P=.01) but not liked (P=.10)
than those without that reference. Retweet and like figures were not statistically significantly different among other categories
and subcategories. The most associated hashtags included references to Japan, mental health, and the youth.
Conclusions: Hikikomori is a repeated word in non-Japanese Western languages on Twitter, suggesting the presence of hikikomori
in countries outside Japan. Most tweets treat hikikomori as a problem, but the ways they post about it are highly heterogeneous
