SoftBank Corp. was added to the list of outside companies that Game8 sends your data to. It gets your device details (country/region, network environment) and your browsing history, and uses them to fine-tune LINE and Yahoo ads. This is one additional recipient on an already long list of ad partners, and it is the same kind of ad-targeting data sharing the policy already described — so the impact is real but bounded.
“LINEヤフー広告ソフトバンク株式会社・デバイス情報(国・地域情報、通信環境など) ・履歴情報(閲覧履歴など) LINEヤフー広告の配信改善のため”
What you can do — Read SoftBank's opt-out and privacy details at https://www.softbank.jp/privacy/personaldata/utilization/ads/ if you don't want your browsing history used for LINE/Yahoo ad targeting. You can also block third-party cookies in your browser to limit this sharing.