Japanese e-commerce redesigns fail when they apply Western minimalism to a market that converts on information density — the design brief needs Japanese buyer psychology at its centre

The brief should specify the required information on each page type before describing the visual direction. For a product page: the mandatory content elements are title, price (with tax display), multiple images (product on white, lifestyle, detail), specifications table, material description, size chart with centimetre measurements, care instructions, delivery estimate, return policy summary, and review section. For category pages: filter and sort options visible above the fold, product card showing price with tax, brief product name, and a trust indicator (number of reviews, or a product flag). For checkout: progress indicator, shipping cost shown before payment step, and order summary visible on the same page as the payment input. The visual brief comes after the content brief, not instead of it.

A Japanese product page that meets buyer expectations contains: a clear product title in Japanese, price displaying tax-inclusive amount, product images from multiple angles including detail close-ups, a specifications table covering all relevant attributes (dimensions in cm, weight in g, materials with percentages, country of manufacture), a size guide with body measurements and garment measurements side by side for apparel, care instructions following JIS care labelling conventions where applicable, a shipping and delivery section with estimated delivery dates by region, a return and exchange policy summary, a social proof section with review count and star breakdown, and a question-and-answer section if the product has common buyer questions. All of this content should be structured in the page template, not added to the product description as unformatted text.

Add LINE integration as an explicit section of the redesign technical specification. For LINE Login: the Shopify or WooCommerce implementation requires a LINE Login channel registered in the LINE Developers console, an OAuth integration connecting LINE user identity to the store's customer record, and a "Login with LINE" button added to the account login and checkout authentication pages. For LINE share: a LINE share button on product pages sends a product image, title, and URL to the buyer's LINE contacts — this requires the LINE Share API script and a share button in the product page template. For LINE mini-app entry points: if the store has a LINE Official Account with a mini-app, the entry points are links placed in the store that open within the LINE app context. All three require different technical implementations and should each be specified separately in the redesign scope.

Platform migration introduces a separate risk layer to a redesign project. If the current platform is functionally adequate for the store's volume and product requirements, redesigning within it is the lower-risk path. Shopify is a more common choice for new Japanese e-commerce projects due to its growing Japanese payment and localisation ecosystem, but migrating an existing WooCommerce store to Shopify involves product data migration, SEO URL mapping, customer data migration, and integration rebuilds — a significant parallel project. If the current platform has specific limitations that are contributing to the conversion problems identified in the audit (slow load times that managed hosting cannot resolve, checkout customisation limitations, inventory management gaps), migration may be justified. In that case, scope the platform migration and the redesign as a single project with a unified QA process.

Establish a clear baseline before the redesign launches: record the conversion rate (transactions divided by sessions) for the 90 days prior to launch, segmented by device type (mobile and desktop separately) and by key product categories. After launch, compare the same metrics for the equivalent post-launch period, controlling for seasonal differences. For a more rigorous measurement, run an A/B test using a percentage of traffic on the old design against the new design for at least three weeks before full launch. In GA4, use the Explorations funnel report to compare the drop-off rates at each stage of the purchase path between the old and new designs. A redesign that improved conversion should show improvement at the specific funnel step it was designed to address — if it was a product page redesign, the add-to-cart rate should improve; if it was a checkout redesign, the checkout completion rate should improve.