Meguro River, very popular cherry blossom (Sakura) viewing spot in Tokyo, offer cherry blossom illumination in Spring. The light up lasts from 6PM to 9PM. from Meguro station (JR Yamanote line, Tokyo Metro Nanboku line, Toei Mita line and Tokyu Meguro line), through Nakameguro station (Tokyu Toyoko line and Tokyo Metro Hibiya line) to Ikejiri-Ohashi station (Tokyu Denentoshi line). For detailed information, see Meguro River: Cherry Blossom.
Around Nakameguro station, many vendors sell foods and drinks, including bears and wines, etc. Those attract many people after working.
Compared to Nakameguro station side, Meguro station side is wider and less crowded. Even if you cannot find any seats in Nakameguro, some restaurants are available on this side.
Meguro River, Chidorigafuchi (Chidorigafuchi: Cherry Blossom – Night View) and Ueno park are the most popular night veiwing spots for cherry blossoms (Sakura). However, Chidorigafuchi area does not have many restaurants and vendors. In this regard, if you wanna see cherry blossoms with eating something, Meguro river would be a good option.