The assessment is based on a highly authoritative and directly relevant primary source. A news article from Nikkei Asia, the organization responsible for calculating the index, explicitly states that the index "gained 4.2%." This is direct evidence that the index closed at a higher value than its previous close. This primary evidence is clear, unambiguous, and comes from a source with maximum credibility on the subject. Other high-relevance sources from the same publisher corroborate that this is the official channel for market news. There is no conflicting evidence among the provided sources. The sources with zero relevance, which are corporate legal notices, have been correctly disregarded as they do not pertain to the index's daily performance. The combination of direct, positive evidence from a top-tier authority results in a high-confidence assessment that the statement is true.