Project Background:

LINE is one of Asia's biggest messaging apps, boasting 82 million monthly active users in Japan alone. As a member of the product planning team, I worked on renewing one of the app's most popular features - the calendar/event feature, as the UI had not been updated and multiple calendar features remained in the app.

Project Goals:

  1. Identifying use cases and user journey
  2. Streamlining event creation process


Duration: 6 months

Users Studied: 10,000+ (Quantitative)

Team Members: Myself (UX researcher), UX Research Lead, Product Managers, Engineers


Competitor Analysis

  • Started by conducting research of competing services in Japan and overseas to identify best practices and how the LINE user flow compares.

Qualitative Data Analysis

  • As LINE had three different event/calendar features, I next used internal analytics tools to track usage of three similar features within the app.
  • These showed that the most popular feature was the RSVP/voting feature.

User Journey Mapping & Brainstorming with How Might We Statements

  • After preliminary research was completed, I joined product teams on a trip to LINE's parent offices in Seoul, South Korea.
  • We held a series of workshops with cross functional teams from both Japan and Korea to map out the user journey for the RSVP/voting feature and brainstorm ways to improve the experience.
User Journey Mapping

Brainstorming Ideas

Rapid Prototyping

  • After the workshops were completed, we returned to Tokyo and began prototyping a new flow.
  • I used Sketch and InVision to create a functioning prototype of a new user flow.
Sketching Ideas
User Flow of Old UI of Event and Calendar Features
User Flow of new UI, combining most used features

A/B Testing

  • UI designers created a final new design based on the above UI, before product managers conducted A/B testing with the existing event feature UI
  • A/B tests showed that the new UI resulted in a lower drop out rate and higher rate of event creation


As a result of the project, one of the most popular features of LINE's chat app was simplified and made easier to use. Usage of the feature increased, and has now been integrated with another LINE product, the AI speaker Clova.


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