The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
The second season was announced on the night the Winter Arc special aired (December 25, 2025 UTC / early December 26 JST), per Crunchyroll and MyAnimeList[2] News.
MyAnimeList[1] News reports the official website announced the second season with a Tozuka illustration.
Wikipedia's Undead Unluck article notes the second season was announced the day the special aired.
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