The site claims [in Japanese]:
"Is behavioral targeting advertising delivery service. Reserves the blog ad (ad network) frame, stocks ad delivery techniques such as behavioral targeting (BT) and retargeting (Retargeting), it provides accurate solutions to advertisers and publishers."
That appears to mean Tracking, and, perhaps, redirecting and/or pop-ups.
None of that is appropriate for children; it is questionable for adults as well.
Note also this from THIS website today:
"Information from third-party sources (1)
WOT uses third-party information, such as listings of phishing and malware sites, to support user ratings and to provide additional information about potential threats. Learn more.."