If the running balance on your Mizuho Financial Group statement does not add up row by row, that is exactly the kind of mismatch Convert·Into is built to catch rather than pass through silently. Every figure in the statement document is verified line by line against the printed closing balance. When a transaction row does not add up, that single row is flagged for your review without rejecting the rest of the file: you see exactly which entry needs attention while every other transaction processes cleanly.
If the Mizuho Financial Group statement you have is a scanned image or a phone photo instead of an exported file, that alone does not stop Convert·Into from reading the transaction table off it. A scanned or photographed statement document is read via OCR and subjected to the same running-balance verification as a digitally generated file. If the scan misreads a character, the balance check catches the discrepancy so a quiet digit error never reaches the export.