Takako Shimura’s Sweet Blue Flowers (Aoi Hana) was serialized between 2004 and 2013. Volume One contains the first seven issues.
When they were separated as children, BFFs Akira Okudaira and Fumi Manjoume vowed to write each other every day. Well …
Years later, they meet again on a train. They’re both travelling to their new high school. They don’t recognize each other and find themselves making friends all over again. Eventually the penny drops. Recognition! Delight! It’s almost as though the intervening years had never been.
Which is good, because Fumi could use a friend.