Border in Bloom

A Border in Bloom is a classic Shoujo manga visual trope, where a character is drawn bordered by flowers. This is most often done to indicate a romantic scene, and may be a visual version of Rose-Colored Glasses.

However, it's also common at other times, including character introductions, important costume changes, feats of courage, or whenever an artist feels like showing off their mad still-life skills.

A floral border is a visual shorthand for saying a person is beautiful, because they belong amongst beautiful flowers, or perhaps a more sexual metaphor. The particular flowers chosen usually represent the character in some way, like a Flower Motif, or the situation the character is in, like showing lilies for lesbian attraction. These might be a form of Hanakotoba symbolism.

Anime and Manga

 * Revolutionary Girl Utena introduces all of its major characters with an ornate border with a spinning rose blossom at each of the four corners of the screen. The roses are colored the same as the character's hair color.  The only characters not introduced this way are Wakaba and Chu-Chu, which is also meaningful.  Wakaba eventually earns her border in Wakaba's Flourishing.
 * In the manga of Sailor Moon, this happens.
 * In UQ Holder! chapter 78, Dana is surrounded by flowers while proclaiming the virtues of love and beauty.
 * In the ED for Minami-ke Tadaima, Haruka gets a Cherry Blossom border as appropriate for a Yamato Nadeshiko. Kana gets violets for her blunt honesty, and Chiaki gets orange maple leafs to suit her melancholic nature.
 * In the OP for Super GALS!, Ran is bordered by by pinkish-purple daisies (maybe osteospermum?). Played With, as her glamour shot quickly gives way to various gag faces.
 * Ouran High School Host Club has roses which symbolizes the hosts, even appearing in front of a still color background along with the host in question.

Video Games

 * Marluxia from Kingdom Hearts, when he swings his infamous scythe, cherry blossoms petals appears.

Web Comics

 * Gunnerkrigg Court offers this amazing example of Robosexual love with roses and violets.

Real Life

 * Weddings are traditionally pretty Shoujo Demographic, so it's not surprising that lots of wedding pictures are framed with white flowers.